HDMI input over CSI2 on RPi5 requires quite a bit more setup, because
/dev/video0 (or other /dev/video*) isn't automatically routed to the
video source. This needs finding relevant source media entity, and then
a route to requested video device (usually /dev/video0). Setting video
format gets more complicated too, because it needs to be set on all
involved nodes (aka "pads").
V4L2_EVENT_SOURCE_CHANGE is delivered on a different FD than reading
stream from, so both needs to be select()ed in this case.
From the user perspective, this adds two new options: --media-device and
--media-entity-name. When provided, ustreamer will find requested entity
and route it to the device given in --device option.
* Add Support fo YUV420 and 410 and YVU variants.
* Add new formats to the help messaging
* Remove YUV410 supprt since M2M encoder on Pi cannot convert it
* Cleanups requested by @mdevaev
* Change to use u8 per @mdevaev
Extension of c96559e4ac.
Some cheap Chinise cameras produces frames which are detected as 'broken'. However they
are later handled well.
Introduce an option which allows disable the check on demand.
