Library code generally shouldn't modify global state, so pw_init()
should not result to changing the C locale.
Instead, set the C locale in main() for tools and daemons.
We'll still setlocale for LC_MESSAGES, to get translated UI elements in
wireplumber. This workaround should be removed eventually...
Make all tools output to stdout (pw-mon mostly) so that we can pipe the
output around.
Send errors to stderr.
fprintf(stdout, ...) -> printf(...)
setlinebuf for stdout so that pipe works better.
See #2110
