[a11y] Make sure RenderFractionalTranslation updates its semantics after the translation field is set (#48985)

Moves the checks that projects have been configured for desktop to a lower level, where they will cover more codepaths (e.g., 'run'), and improves them to check for native build projects, rather than just directories, to catch cases where the directory exists (e.g., due to accidental creation of generated files).

Also adds links to the error messages pointing to instructions on adding desktop support to a project.

Fixes #47145

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* implicit-casts:false on flutter_tools

* use castStringKeyedMap

* address review comments

* address review comments

* fix issues after rebase

This reverts commit 3597bae6.

...because otherwise, processes that think they're manipulating your
filesystem will be doing crazy things the test is ignoring, leading to
(at best) failures and (at worst) flakes or disk corruption.

Currently Linux builds override the default BUILD mode by putting it in
the generated config. That makes it sticky for manual runs of make,
which is inconsistent with how other platforms work.

Instead, pass the build mode as a command-line override, the same way
someone would if building directly with make. This makes the flow of
controlling the mode less confusing.

Fixes #41528

* [flutter_tool] Report to analytics when the tool is killed by a signal

* Fix analyzer lint

Moves the generated config into that directory. Matches the structure of
the other desktop projects.

Also fixes #40265

When building in profile or release mode on desktop, add a prominent
warning that it's actually a debug build. This is to help address issues
with people being unaware of the current state of builds due to
following third-party guides rather than official documentation.

macOS is not included since PRs are in flight for macOS release support.

This reverts commit bd52a78c.

Move tools tests into a general.shard directory in preparation to changing how we shard tools tests (#36108)

- Adds desktop projects to ApplicationPackageStore
- Plumbs target overrides through the desktop builds

* Re-enable const