Let the caller decide if stdout and stderr must be inherited on process
creation, i.e. if stdout and stderr of the child process should be
printed in the scrcpy console.
This allows to get output and errors for specific adb commands depending
on the context.
PR #2827 <https://github.com/Genymobile/scrcpy/pull/2827>
The current process could be waited both by run_file_handler() and
file_handler_stop().
To avoid the race condition, wait the process without closing, then
close with mutex locked.
There were two versions: process_wait() and process_wait_noclose().
Expose a single version with a flag (it was already implemented that way
internally).
The function process_wait() returned a bool (true if the process
terminated successfully) and provided the exit code via an output
parameter exit_code.
But the returned value was always equivalent to exit_code == 0, so just
return the exit code instead.
