Debugger: Fix #11411.

CliContext/CommandLineUserInterface:
- Process the debug report event asynchronously. The missing lock that
  was fixed in commit 5ac34e5a78305abac4c758a34db9f1e34aee54ed highlighted
  a problem in how the CLI was handling the case where it was intended to
  exit immediately after saving a report, since it issued the quit request
  directly from the report event handler. This resulted in locking issues,
  as the team debugger would then attempt to tear itself down, during which
  it needs to acquire the team lock. However, that was already being held
  by the thread in which the CLI was initiating the quit, resulting in a
  deadlock.