Reland of #134031. (Reverted in #135069.) Contains the fix for b/301051367 together with cl/567233346.

Support for FFI calls with `@Native external` functions through Native assets on Linux. This enables bundling native code without any build-system boilerplate code.

For more info see:

* https://github.com/flutter/flutter/issues/129757

### Implementation details for Linux.

Mainly follows the design of https://github.com/flutter/flutter/pull/130494.

Some differences are:

* Linux does not support cross compiling or compiling for multiple architectures, so this has not been implemented.
* Linux has no add2app.

The assets copying is done in the install-phase of the CMake build of a flutter app.
CMake requires the native assets folder to exist, so we create it also when the feature is disabled or there are no assets.

### Tests

This PR adds new tests to cover the various use cases.

* packages/flutter_tools/test/general.shard/linux/native_assets_test.dart
  * Unit tests the Linux-specific part of building native assets.

It also extends various existing tests:

* packages/flutter_tools/test/integration.shard/native_assets_test.dart
  * Runs (incl hot reload/hot restart), builds, builds frameworks for Linux and flutter-tester.

Reverts flutter/flutter#134031

context: b/301051367
Looked at the error message from the broken TAP target, but seems like the failure might be non trivial to resolve. Would it be okay if we revert this for now while it is being triaged?

Support for FFI calls with `@Native external` functions through Native assets on Linux. This enables bundling native code without any build-system boilerplate code.

For more info see:

* https://github.com/flutter/flutter/issues/129757

### Implementation details for Linux.

Mainly follows the design of https://github.com/flutter/flutter/pull/130494.

Some differences are:

* Linux does not support cross compiling or compiling for multiple architectures, so this has not been implemented.
* Linux has no add2app.

The assets copying is done in the install-phase of the CMake build of a flutter app.
CMake requires the native assets folder to exist, so we create it also when the feature is disabled or there are no assets.

### Tests

This PR adds new tests to cover the various use cases.

* packages/flutter_tools/test/general.shard/linux/native_assets_test.dart
  * Unit tests the Linux-specific part of building native assets.

It also extends various existing tests:

* packages/flutter_tools/test/integration.shard/native_assets_test.dart
  * Runs (incl hot reload/hot restart), builds, builds frameworks for Linux and flutter-tester.

Partial work towards https://github.com/flutter/flutter/issues/132245.

I also couldn't help myself to do a very minor refactor and add some comments to `LocalEngineInfo` because I was getting confused myself implementing it.

Part of https://github.com/flutter/flutter/issues/47161

flutter-tool: enum cleanup

fix devtool instructional messages after `flutter build ... --analyze-size `.  Fixes #122229 (#122230)

fix devtool instructional messages after `flutter build ... --analyze-size `.  Fixes #122229

You can now specify a --local-web-sdk flag to point to a wasm_release folder. This will make it so that only artifacts that pertain to the web sdk are overridden to point to the wasm_release folder. Other artifacts (such as impellerc) will pull from the cache, or from the --local-engine path if that is specified.

This also uses precompiled platform kernel files for both ddc and dart2js

Revert "[web] Add `--local-web-sdk` flag and use precompiled platform kernels for dart2js and ddc (#114639)" (#115242)

This reverts commit 0e9ee367.

* Dart2JS build step looks for compiled platform binaries.

* Use new locations of platform binaries.

* Added --local-web-sdk command line flag.

* Need to use the matching frontend server when doing ddc stuff.

* Update packages/flutter_tools/lib/src/test/web_test_compiler.dart
Co-authored-by: Mouad Debbar <mouad.debbar@gmail.com>

* Update packages/flutter_tools/lib/src/runner/flutter_command_runner.dart
Co-authored-by: Mouad Debbar <mouad.debbar@gmail.com>

* Formatting issues.

* Need to use URI format for platform dill.

* Fix resident runner tests.

* Fix analysis issue.

* Fix and add unit tests.

* Add some useful comments.

* Refine doc comments for flags.
Co-authored-by: Mouad Debbar <mouad.debbar@gmail.com>

Previously developers had to edit their `Runner.rc` file to update their executable's version information. Now, version information will automatically be set from `flutter build`'s arguments or the `pubspec.yaml` file for new projects. 

Addresses https://github.com/flutter/flutter/issues/73652

When desktop support is not present in an existing project, certain
flutter tool commands raise an error that direct the user to
documentation on how to add desktop support to an existing Flutter
project. In a recent revamp of the webside, the URL was very slightly
changed (flutter.dev -> docs.flutter.dev).

This updates the error message to output the new URL.

Issue: https://github.com/flutter/flutter/issues/94398

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

* Add text to --analyze-size command output to launch DevTools with size data.

Remove "This is taking a long time" progress timeout and TimeoutConfiguration.

Revert "[flutter_tools] reland: fold process resolution logic into the flutter tool (#67957)" (#67968)

This reverts commit bd813879.

Reland of #67669

The flutter tool has a number of crashes on stable where an ArgumentError is thrown due to the process manager not being able to resolve an executable.

So that we can adjust/modify this logic, fold it into flutter and add some additional logging.
caches the resolved executable per target directory, to avoid repeated look ups.
Instead of throwing an argument error, attempts to run the executable as given if an exact path can't be found
Accept files or symlinks for the executable path.
user where/which to resolve path instead of package:process logic.

This reverts commit 10c78c26.

The flutter tool has a number of crashes on stable where an ArgumentError is thrown due to the process manager not being able to resolve an executable. Fold the resolution logic into the tool and use where/which instead of the package:process specific logic.

Removes the template version from the Windows template; the API and
tooling boundary will now be considered stable, so there will no longer
be frequent breaking changes.

Also updates the link for adding desktop support to a project for all
three platforms to reflect the current location.

Fixes https://github.com/flutter/flutter/issues/52748