To specify the dill file that will be used to initialize the resident
compiler, instead of the default cached version.

* Add 'v' hotkey to open DevTools in the browser

Also, refactor internal code to do the same.

See https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#avoid-double-negatives-in-apis

Co-authored-by: Zachary Anderson <zanderso@users.noreply.github.com>

[flutter_tools] replace MockFlutterVersion usage with fake where possible, move from context (#77390)

[flutter_tools] refactor devtools handler to expose single method for run/attach and restart (#75807)