Allow event_loop integration with LimaCCDs

This allow to add an event loop to the Lima tango device.

As result our simulator can be interoperable with Qt.

Sounds like it it can fix a lot of our interoperability problem with BLISS.

This now can be used this way in our simulators in BLISS:

import gevent

def process_gevent():
    try:
        gevent.sleep(0.01)
    except Exception:
        _logger.critical("Uncaught exception from gevent", exc_info=True)

result = LimaCCDs.main(event_loop=process_gevent)
sys.exit(result)

@matias.guijarro could you please check if you think it's fine?