* Add flag to enable expression evaluation for web

Added flag --web-enable-expression-evaluation to flutter run commmand
that enables expression evaluation from IDEs for web target. Disabled
by default.

Helps https://github.com/flutter/flutter/issues/54520

* Update packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart
Co-Authored-By: Jonah Williams <jonahwilliams@google.com>
Co-authored-by: Jonah Williams <jonahwilliams@google.com>