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

* Minor adjustment for engine change, and rev template version

* whitespace fix

* First pass at CMake files; untested

* First pass of adding CMake generation logic on Windows

* Misc fixes

* Get bundling working, start incoprorating CMake build into tool

* Fix debug, exe name.

* Add resources

* Move cmake.dart

* Rip out all the vcxproj/solution plumbing

* Fix plugin cmake generation

* Build with cmake rather than calling VS directly

* Adjust Windows plugin template to match standard header directory structure

* Pass config selection when building

* Partially fix multi-config handling

* Rev template version

* Share the CMake generation instead of splitting it out

* VS build/run cycle works, with slightly awkward requirement to always build all

* Update manifest

* Plugin template fixes

* Minor adjustments

* Build install as part of build command, instead of separately

* Test cleanup

* Update Linux test for adjusted generated CMake approach

* Plugin test typo fix

* Add missing stub file for project test

* Add a constant for VS generator

PR #57749 included changes to the way the project interacts with the
build process (e.g., bundling the necessary library), so should have
incremented the template version to trigger the messaging to developers.

Updates the Windows app template to use the new DartProject API, significantly simplifying the template.

Increments the template version, even though this isn't itself a breaking change, so that users will be prompted to update their projects rather than be broken later when the old API is removed.

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