* implicit-casts:false on flutter_tools

* use castStringKeyedMap

* address review comments

* address review comments

* fix issues after rebase

* Reland: [flutter_tool] Fuchsia AOT builds

* Fixes

This reverts commit a57dddd2.

* [flutter_tool] Use engine flutter_runner prebuilts

* Update packages/flutter_tools/lib/src/fuchsia/fuchsia_build.dart
Co-Authored-By: Jonah Williams <jonahwilliams@google.com>

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.

This is a partial re-application of #24669, which was
reverted due to Fuchsia breakages.

https://github.com/flutter/flutter/issues/24413

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

This relands flutter/flutter#33163 with a fix to the integration_ui test.

* Clean up some flutter_tools tests

* Remove arbitrary retry that happens even for fundamental errors, and generally clean up _DevFSHttpWriter.

* Update dependencies (requires fixes; see next commit)

* Fixes for new dependencies.

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

* Revert "Replace netls and netaddr with dev_finder (#26090)"

This reverts commit eee154af.