* 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

Reland: Ensure that flutter run/drive/test/update_packages only downloads required artifacts  (#30254)

Revert "Ensure that flutter run/drive/test/update_packages only downloads required artifacts (#30075)" (#30232)

This reverts commit 3fd36200.

This reverts commit 76061c4f.

This reverts commit 98971f3c.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Fixes resulting from audit of issues links

I looked at every link to GitHub in our repo. For cases where we had a TODO that was waiting for a bug to be fixed, and the bug has now been fixed, I applied the pending change. For cases where the link was out of date, I updated the link.

* Update run_test.dart

skip this test again since it failed on linux and macos bots

* Remove uses of deprecated constants
* Change int.parse to int.tryParse where appropriate

The new values are not ready for use yet inside Google

* Roll engine to e976be13c51448f89107d082ec81e2b6731671fa

* move away from deprecated constants

Creates a new (hidden) flutter command 'ide-config' that will create and/or update
existing .iml files and some files under the .idea directory, as well as
removing existing *.iml files and the .idea directory.

It also:

 * Adds *.iml to the .gitignore
 * Removes existing .iml files from the repo, and moves them to the
   packages/flutter_tools/ide_templates/intellij directory.
 * Adds a flag to ide-config ('--update-templates') that will take any new .iml
   files in the flutter tree and add them to the existing templates.
     - If --overwrite is also specified, then all existing templates will also
       be overwritten with the contents from the flutter tree, and any that have
       been deleted from the flutter tree will also be removed from the
       templates.
 * Added new run configurations for all existing app targets that will now also
   be automatically added to IntelliJ.
 * Setting up the environment also includes setting the coding style guidelines
   and the git VCS.
 * Note that after this PR lands, Flutter developers will need to run it once to
   re-create the .iml files and configuration files that have been removed.

After this PR lands, .iml files will no longer appear in the untracked files
section for git.