[lldb-dap] Report exit status message in lldb-dap, same as lldb cli (#89405)

Summary:
When the target inferior process that is being debugged exits in lldb
command line, it emits following message:
`Process 4049526 exited with status = -1 (0xffffffff) debugserver died
with signal SIGTERM`
lldb-dap on the other hand does not emit a similar message. This PR adds
the same status message to lldb-dap.

Test Plan:
In VSCode debug any target and hit stop mode, kill lldb-server and
observe an exit status message similar to the following: Process 2167677
exited with status = -1 (0xffffffff) debugserver died with signal
SIGTERM

Reviewers:
@jeffreytan81,@clayborg,@kusmour,

Subscribers:

Tasks:
lldb-dap

Tags:
GitOrigin-RevId: ef2ca97f48f1aee1483f0c29de5ba52979bec454
4 files changed