Listen for `setBreakpoint` on `debugger.js` and add the relevant WebIDLs
and Servo counterparts to trigger this event and notify SpiderMonkey.
Implement `find_source` for `SourceManager` and `find_offset` for
`SourceActor`.
Testing: Manual testing and `./mach test-devtools` (note, the latter
seems to have some failing tests, we are investigating this, but this
patch doesn't add any new failure).
Fixes: Part of #36027
---------
Signed-off-by: eri <eri@igalia.com>
Co-authored-by: atbrakhi <atbrakhi@igalia.com>
