Always use the canvaskit path from the web sdk.

Revert "[flutter_tools] Remove sound null safety flag (#123031)"

[flutter_tools] Remove sound null safety flag #2

This reverts commit 7c3088cf.

[flutter_tools] Remove sound null safety flag

[web] Ensure CanvasKit is served from the correct location

This reverts commit 0fb4406c.

This reverts commit e03029ef.

* dart fix --apply

* manual fixes

* fix after merge conflicts

* review

* Work in progress.

* Some fixes to the command line.

* Bootstrapping works.

* Change kickoff order to maximize concurrency.

* Fix analyzer errors and formatting issues.

* Fix doc comment.

* Added unit tests for some of the web targets.

* Format issue.

* Add an integration test that builds an app to wasm.

* Add a todo for depfiles.

* Formatting.

* Apparently the license header needs to say 2014.

* `file://` URIs confuse dart2wasm on Windows. Just use absolute paths.

* Update unit tests to match new path passing.

* Have a distinct build directory for wasm, and fixes for some upstream changes.

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>

This reverts commit 00658736.

* Use `dart __deprecated_pub` instead of `pub` to invoke pub from tools

The top level `pub` commmand has been deprecated and will print
a message. It is however implemented via the __deprecated_pub command
that prints no message.

This reverts commit a1020512.

Allow flutter run to work end-to-end with a UWP device.

Uses win32/ffi for the actual launch of the application, injected via
the native API class. This is structured to avoid a g3 dependency.

Install and amuid require powershell scripts for now.

Actually connecting to the observatory requires running a command in an
elevated prompt. Instructions are presented to the user if a terminal is
attached.

This is a rebased version of https://github.com/flutter/flutter/pull/79684
by @jonahwilliams, updated to remove `NativeApi` and replace is with calls
to `uwptool`.

Part of https://github.com/flutter/flutter/issues/82085