* [flutter_tools] [dap] Ensure DAP sends app.stop/app.detach during terminate

Fixes an issue where the flutter_tester device may not be cleaned up correctly if we just terminate the Flutter process.

* Update integration test expectations

* Revert accidental commit

Since https://github.com/dart-lang/sdk/commit/02d9c3e6a586ad47909262931375f25abb34b4e3 this flag does absolutely nothing. The behaviour it controlled is now automatic and the flag is not required.

The flag will be removed from the Dart SDK in the future after Flutter is no longer using it.

Provide more useful error message if a non-compliant DAP tool (or user) sends bad input to DAP server (#107827)

* [flutter_tools] [dap] Add support for passing env variables to spawned processes

* Use named args

* Use in-memory fs and FakePlatform

* Pass filesystem style to MemoryFileSystem

* Fix issues running integration tests through DAP

These adapters were incorrectly trying to connect a DDS instance even when Flutter would create its own. This change disables DDS in the DAP layer and leaves it to Flutter (although it passes `--no-dds` on to Flutter if provided to the DAP process).

Also fixes an issue where we would unnecessarily connect the VM Service for tests even in 'noDebug' mode because of a change/fix that now includes a 'vmServiceUri' in the `test.startedProcess` event.

* Don't terminate Dart process pids from VM Service

These processes may be on another device, and in the case of attach the debugee should not be terminated anyway.

* Add support for attachRequest in DAP, which runs "flutter attach"

* Update DAP docs for attachRequest

* Improve doc comments

* Fix comments

* Remove noDebug from attach + create a getter for `debug`

* Fix indent

* Add support for running tests through debug-adapter

* Improve comments about stdout + remove pedantic