PR provides a new option to the `test` command to include coverage info of specified packages.  
It helps collecting coverage info in test setups where test code lives in separate packages or for multi-package projects.
At present, only current package is included to the final report.

Usage:

Consider an app with two packages: `app`, `common`.
Some of the tests in `app` use (indirectly) code that is located in `common`. When running with `--coverage` flag, that code is not included in the coverage report by default. To include `common` package in report, we can run:

```sh
flutter test --coverage --coverage-package app --coverage-package common
```

Note that `--coverage-package` accepts regular expression. 

Fixes https://github.com/flutter/flutter/issues/79661
Fixes https://github.com/flutter/flutter/issues/101486
Fixes https://github.com/flutter/flutter/issues/93619

Roll to engine to 4f4486b00be28183b482bbb74bbed25f4db153fe  pick up dart to 3.1.0-169.0.dev.
Changes since last roll
```
4f4486b00b Roll dart to 3.1.0-169.0.dev (#42602)
```

Manual roll since rolling to dart 3.1.0-169.0.dev requires patching to expression evaluation in flutter tools

Replace imports of `src/remote_listener.dart` with `backend.dart` which exports `RemoteListener`.

Remove the unused imports of `src/backend/stack_trace_formatter.dart` (no uses of `StackTraceFormatter`) and
`src/backend/suite_channel_manager.dart` (no uses of `SuiteChannelManager`).

Close https://github.com/flutter/flutter/issues/125940

I will add tests if this PR looks roughly OK :)

The fix mainly mimics https://github.com/flutter/flutter/pull/115160 - just remove the default argument.

p.s. I ran into this bug when wanting to set concurrency in my dart_test.yaml for one set of my tests which I need to be executed without parallalization.

The latest version of `test_api` removed the deprecated annotation for a couple libraries. The deprecations had been a hack to avoid usage from inappropriate places, but they cause trouble and likely weren't effective for that goal.

Remove separate import for `registerException` since that was also moved to be available from the top level `scaffolding.dart` library.

`flutter test` wasn't awaiting the `_serveObservatory` request which was
causing a race condition in the `flutter test should respect
--serve-observatory` test in `test/integration.general/test_test.dart`.

Related to https://github.com/flutter/flutter/issues/123516

Originally reverted due to a misattributed hot reload benchmark
regression.

This reverts commit f5bce716.

Always use the canvaskit path from the web sdk.

This reverts commit c3de9015.

Also clean up messaging output by `flutter test` when `--start-paused` is provided.

Revert "[flutter_tools] Remove sound null safety flag (#123031)"

Remove 1745 decorative breaks

[flutter_tools] Remove sound null safety flag #2

This reverts commit 7c3088cf.

[flutter_tools] Remove sound null safety flag

Revert "[web:tools] always use CanvasKit from the cache when building web apps (#93002)"

This reverts commit 275ab9c6.

Revert "Reland "Remove references to Observatory (#118577)""

* [flutter_tools] Add support for URI formats like ?line=x for "flutter test"

* Remove unnecessary function

* Handle parsing absolute paths on Windows

* Use Windows-style paths when running on Windows

* Fix paths in isFile

* Remove unnecessary clear

This reverts commit 298d8c76.

* allow passing --file-reporter option to test running refs #69425

* Add trailing comma to help to meet style requirements

* Add space between tests for clarity

---------
Co-authored-by: daniel-v <dvarga@skawa.hu>

* lerp documentation

* Remove Note, Note That from repo

* Improve BorderSide documentation.

* apply review comments

This reverts commit 2df140f4.

* wip run_local_linter.dart

* get run_local_linter.dart working

* slow working implementation

* speed up run_local_linter.dart

* fix run_local_linter.dart

* remove catchError

* another fix

* fix another

* fix

* more fixes

* fix moar

* fix moar

* fix

* finish

* fix tests

* clean up further

* code review

* delete run_local_linter.dart

Observatory is being deprecated for Dart 3.0 so it should no longer be
referenced in tooling messaging / flags.

See https://github.com/dart-lang/sdk/issues/50233

This reverts commit 254a796b.

Revert "Reland "Add --serve-observatory flag to run, attach, and test (#118402)" (#119529)" (#119729)

This reverts commit 7477d7ac.

* Reland "Add --serve-observatory flag to run, attach, and test (#118402)"

This reverts commit 86ab01d2.

* Fix flaky failures

* Fix VM service disappearing failure

This reverts commit 6cd4fa45.

* Remove superfluous words from comments.

* Revert `win32_window.h`

Which seems to come from `gallery`

This flag will allow for Observatory to be served by the VM service once it is disabled by default in the Dart SDK.

The changes to the Dart SDK have rolled so the backward compatibility
is no longer needed.

* dart fix --apply

* manual fixes

* fix after merge conflicts

* review

Matches new location in the Dart SDK.
https://dart-review.googlesource.com/c/sdk/+/275482

Includes fall back logic so the old file location will continue to be used
until the new location change lands. Then we can remove the logic and only
use the new location in a future change.

Issue: #118119

* Use file:/// style uris when passing platform to the compiler.

* License header.

* Use BufferLogger.

* Don't unadvertently convert strings to regexes for matching purposes.

* Fix formatting.

* More formatting.

You can now specify a --local-web-sdk flag to point to a wasm_release folder. This will make it so that only artifacts that pertain to the web sdk are overridden to point to the wasm_release folder. Other artifacts (such as impellerc) will pull from the cache, or from the --local-engine path if that is specified.

This also uses precompiled platform kernel files for both ddc and dart2js

* remove all body_might_complete_normally_catch_error ignores

* add a test