* 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/lib

* address review comments

* use castStringKeyedMap

* introduce {bool,string,strings}Arg

* fix ci

Fix some places where Debug/Release was treated as a binary switch.

Makes similar changes to Windows and Linux to simplify adding profile
support to those platforms in the future. This means `--profile` builds
will fail on Linux and Windows for now, but that's fine since they
aren't actually supported, and unlike `--release` don't provide useful
functionality at the native code level.

Also fixes 'stopApp' always using Debug on macOS, to avoid showing an
error when running Profile (or Release).

Fixes #33203

We were using the `defaults` command-line utility to parse
Plist files, but it was never supported by Apple, and it
appears that in an upcoming OS release, it will be less likely
to work:

> WARNING: The defaults command will be changed in an upcoming
> major release to only operate on preferences domains. General
> plist manipulation utilities will be folded into a different
> command-line program.

Fixes https://github.com/flutter/flutter/issues/37701

Instead of requiring a name_output.sh, expect a file called
.app_filename in the macos/Flutter directory containing just the name of
the application. The expectation is that the Xcode build will create
that file with a script.

This is not intended as a long-term solution, but it's a substantial
improvement over name_output.sh:
- name_output.sh required constructing the full build output path; this
  made sense when it was coupled with build.sh, but now that the
  decision for where build output goes lives in flutter_tool, that logic
  should as well.
- Changing the name of the application required also updating
  name_output.sh, which is error-prone. With .app_filename, it can be
  created using $PRODUCT_NAME, which means that the usual way of setting
  the application name will automatically update this flow as well.

Part of #30706

* fix some formatting issues

* address review comments

* fix indent