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

This reverts commit 275ab9c6.

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

This reverts commit 298d8c76.

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

* dart fix --apply

* manual fixes

* fix after merge conflicts

* review

Speedup coverage test runs by using (new) coverage handle with caching.

On a `flutter test --coverage` run on `packages/flutter` the runtime goes from ~828 seconds to ~617 seconds, or a ~25% reduction in time spent (testing without coverage takes ~236 seconds so the overhead of `--coverage` in this case goes from ~592 seconds to ~381 seconds, or a ~35% reduction).

In https://github.com/flutter/flutter/pull/103771, we rolled
dependencies in Flutter, which triggered an update of package:coverage
to v1.3.1. The new version includes
https://github.com/dart-lang/coverage/pull/370 in which two deprecations
landed:

* The `Resolver` default constructor was deprecated and replaced with
  the `Resolver.create` static factory method, which unfortunately
  happens to be async.
* The `packagesPath` parameter to `HitMap.parseJson`, which takes the
  path to the `.packages` file of the package for which coverage is to
  be collected, was deprecated. This parameter was replaced with
  `packagePath` in https://github.com/dart-lang/coverage/pull/370 which
  was part of the overall deprecation of the .packages file in Dart
  itself https://github.com/dart-lang/sdk/issues/48272. The overall goal
  being that end-user code shouldn't need to know about implementation
  details such as whether dependency information is stored in a
  .packages file or a package_info.json file, but rather use the
  package_config package to obtain the package metadata and perform
  other functions such as resolving its dependencies to filesystem
  paths. packagesPath was replaced by packagePath, which takes the path
  to the package directory itself. Internally, package:coverage then
  uses package_config to do the rest of the package/script URI
  resolution to filesystem paths.

This migrates off the deprecated `packagesPath` parameter to the
replacement `packagePath` paramter.

Issue: https://github.com/flutter/flutter/issues/103830

* Use libraryFilters flag to speed up coverage collection

* Allow libraryNames to be null

* Unconditionally enable the reportLines flag

* Fix analysis errors

Roll dependendencies

This rolls depdendencies to latest using
flutter update-packages --force-upgrade

This change includes three code changes:

* Removes charcode from the dependencies allowlist since it no longer
  appears in the transitive closure of dependencies of the flutter,
  flutter_test, flutter_driver, flutter_localizations, and
  integration_test packages.

* Uses Resolver.create instead of the deprecated Resolver constructor.
  The default Resolver constructor has been deprecated in favour of the
  static Resolver.create() factory function, which unfortunately happens
  to be async. Propagated the async-ness up the chain.
  This change was partially reverted and the deprecation ignored in this
  patch until package:coverage can be rolled internally at Google.

* Eliminates the use of the deprecated packagesPath parameter to
  HitMap.parseJson. This parameter was deprecated and replaced with
  packagePath in https://github.com/dart-lang/coverage/pull/370 which
  was part of the overall deprecation of the .packages file in Dart
  itself https://github.com/dart-lang/sdk/issues/48272. The overall goal
  being that end-user code shouldn't need to know about implementation
  details such as whether dependency information is stored in a
  .packages file or a package_info.json file, but rather use the
  package_config package to obtain the package metadata and perform
  other functions such as resolving its dependencies to filesystem
  paths. packagesPath was replaced by packagePath, which takes the path
  to the package directory itself. Internally, package:coverage then
  uses package_config to do the rest of the package/script URI
  resolution to filesystem paths.
  This change was partially reverted and the deprecation ignored in this
  patch until package:coverage can be rolled internally at Google.

This is a pre-update prior to updating flutter_template_images in
https://github.com/flutter/flutter/pull/103739

Issue: https://github.com/flutter/flutter/issues/103371
Issue: https://github.com/flutter/flutter/issues/103775
Issue: https://github.com/flutter/flutter/issues/103830

When re-applying the partially-reverted changes to code coverage,
we'll need to patch host_entrypoint.dart internally to await the Future
that we'll be returning rather than a non-async value.

* Use the report lines flag

* Handle major version bumps in the version check

* Fix existing tests and add a new test

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

HACKTOBERFEST

This reverts commit df02518d.

https://github.com/dart-lang/coverage - 0.14.0 added the ability to be able to ignore coverage depending on comments.

// coverage:ignore-line to ignore one line.
// coverage:ignore-start and // coverage:ignore-end to ignore range of lines inclusive.
// coverage:ignore-file to ignore the whole file.

Finishes the gradual vm service migration by deleting the flutter tooling's vm_service