cleanup: remove `debugger-module-names` flag from all code

[annagrin]

parent issue: dart-lang/webdev#1692

Proposed fix

make server paths follow directory structure:packages/<package_directory>/<path from package root to the file on disk>

Fix plan

• cleanup:
  • set debugger-module-names to true by default
  • after all the changes propagated to dart and flutter stable versions
    • remove passing of the flag by tools
    • remove the flag

[annagrin]

Update: we might just reuse the existing --debugger-module-names flag instead. THen this issue would be the same as flutter/flutter#52693