Refactor DebugReportGenerator to use jobs.

- Instead of asking nodes to resolve themselves directly,
DebugReportGenerator now uses the interface listener to ask the
debugger's workers to resolve them on its behalf.

Fix crash in TeamDebugger.

- TeamDebugger's destructor was assuming the report generator object
had always been created, which might not be the case. Fixes second
part of #9273.

Fix double free.

Fix #9221.

- When an image creation notification is received, the thread
that provoked it needs to be suspended until the debugger has
finished loading the image's debug information. Otherwise, if that
image had a breakpoint in it, it was possible that the thread would
execute past the code where the breakpoint should be before the
debugger had a chance to actually install it.

- Only update breakpoints when debug info loading has actually finished.

Rework control flow for debug report generator.

- DebugReportGenerator is now its own BLooper that generates reports asynchronously
instead of in TeamDebugger's message loop.
- If a stack trace isn't yet available, DebugReportGenerator now waits for it to
be generated.
- Extended Team to add a listener event for report generation completing. DebugReportGenerator
now generates such an event when it has finished writing a report.

Tie DebugReportGenerator into TeamDebugger.

- Add UI listener hook. Still needs to be exposed via the actual
UI though.

Code reorganization.

Rework control flow for debug report generator.

- DebugReportGenerator is now its own BLooper that generates reports asynchronously
instead of in TeamDebugger's message loop.
- If a stack trace isn't yet available, DebugReportGenerator now waits for it to
be generated.
- Extended Team to add a listener event for report generation completing. DebugReportGenerator
now generates such an event when it has finished writing a report.

Tie DebugReportGenerator into TeamDebugger.

- Add UI listener hook. Still needs to be exposed via the actual
UI though.

Code reorganization.