Updates the Linux templates to use CMake+ninja, rather than Make, and updates the tooling to generate CMake support files rather than Make support files, and to drive the build using cmake and ninja.

Also updates doctor to check for cmake and ninja in place of make.

Note: While we could use CMake+Make rather than CMake+ninja, in testing ninja handled the tool_backend.sh call much better, calling it only once rather than once per dependent target. While it does add another dependency that people are less likely to already have, it's widely available in package managers, as well as being available as a direct download. Longer term, we could potentially switch from ninja to Make if it's an issue.

Fixes #52751

Fixes #56194

Remove caching of FlutterView and poll forever if the list of flutter views is empty. Added test for missing release mode logic.

This reverts commit 209bdcb6.

Remove caching of FlutterView. Perhaps the FlutterView RPC might return an empty list if the VM is not quite up yet? We had some old logic to poll the flutter views RPC for up to 200ms. That doesn't seem like a great approach, so instead we could forgo it entirely and trust that either the views come up before the developer tries to interact, or we crash.

Revert "[flutter_tools] default tree-shake-icons to enabled and improve performance (#54923)" (#55413)

This reverts commit 0b93a921.

Adds initial support for flutter create of apps and plugins. This is derived from the current FDE example app and sample plugin, adding template values where relevant.

Since the APIs/tooling/template aren't stable yet, the app template includes a version marker, which will be updated each time there's a breaking change. The build now checks that the template version matches the version known by that version of the tool, and gives a specific error message when there's a mismatch, which improves over the current breaking change experience of hitting whatever build failure the breaking change causes and having to figure out that the problem is that the runner is out of date. It also adds a warning to the create output about the fact that it won't be stable.

Plugins don't currently have a version marker since in practice this is not a significant problem for plugins yet the way it is for runners; we can add it later if that changes.

Fixes #30704

Move Flutter Gallery to dev/integration_tests/ as it is an older copy used only for testing. The current version of the Flutter Gallery now lives in https://github.com/flutter/gallery.

This reverts commit 20bf43b9.

Revert "[flutter_tools] Allow providing dart-defines to Android, iOS, macOS builds (#51714)" (#52041)

This reverts commit ee60eeea.

Adds initial support for `flutter create` of apps and plugins. This is derived from the current FDE example app and sample plugin, with a few changes:
- Added template values where it makes sense.
- Moved some likely-to-change values into separate files for now, to simplify the delete/recreate cycle that will be necessary until it's stable.
- Added some minor Makefile flag handling improvements

Since the APIs/tooling/template aren't stable yet, the app template includes a version marker, which will be updated each time there's a breaking change. The build now checks that the template version matches the version known by that version of the tool, and gives a specific error message when there's a mismatch, which improves over the current breaking change experience of hitting whatever build failure the breaking change causes and having to figure out that the problem is that the runner is out of date. It also adds a warning to the `create` output about the fact that it won't be stable.

Now that the new schema is supported on the stable channel, and the old
schema is considered legacy, the template should always create plugins
using the new schema.