Add logic to set `FIN` flag automatically for transmitted WS frames, but
if `fragmented` option set indicating an expert/manual mode, then the
`FIN` flag is set according to the `final` option.
Since the recent refactoring of spi bus_lock comonent introduced heavy logging under debug/verbose level of verbosity, the http-server test executed in the CI became less stable due to complicated regex. Fixed by removing the first optional group
