[dartdev] `dart install`

This CL adds three new commands to `dart`:

```
Global
  install     Install a Dart CLI tool for global use.
  installed   List globally installed Dart CLI tools.
  uninstall   Remove a globally installed Dart CLI tool.
```

These commands are intended to replace `dart pub global` subcommands
while adding support for `hook/build.dart` and building packages in
AOT instead of running them with JIT.

Internal design doc: http://go/dart-install-cli.

Implementation details:
* The source of truth is the state of the file system. These commands
  write and read directories, files, and symlinks.
* App bundles and symlinks are placed in `DART_DATA_HOME` as per
  http://go/dart-data-home.
* On Unix systems we use symlinks and on Windows batchfiles to place
  executables in the bin directory that point to an application
  bundle. (These OS differences have been encapsulated in a single
  class.)
* On Windows, when an application is running, trying to re-install it
  will fail.

Test coverage:
* Installing from hosted, git, and local paths.
* Installing a package with hooks.
* Installing a package with hooks and user-defines.
* Surfacing build hook failures during install.
* Installing packages with conflicting executables names. This tests
  `--overwrite` flag behavior.
* Installing a new or the same version, this should simply succeed.
* A warning is shown if the bin directory is not on the `PATH`.
* Running an installed app reports the correct exit code on exit.
* Listing all installed versions, including the versions not on
  the`PATH`.
* Uninstalling, which uninstalls all versions.
* Re-installing while it is running.
* Uninstalling while it is running.

Out of scope for initial version:
* Saving the SDK version (to display in `dart installed`).
* Short-circuiting if re-installing an exactly installed version.

Bug: https://github.com/dart-lang/sdk/issues/60889
Change-Id: I8f3a60d26e013957ce6fd7f52e564bcaaff30509
Cq-Include-Trybots: luci.dart.try:pkg-linux-debug-try,pkg-linux-release-arm64-try,pkg-linux-release-try,pkg-mac-release-arm64-try,pkg-mac-release-try,pkg-win-release-arm64-try,pkg-win-release-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/441581
Reviewed-by: Sigurd Meldgaard <sigurdm@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Michael Goderbauer <goderbauer@google.com>