libcamera: remove unsupported ffc preview size

librotation.so crashes if the preview size is not 640x480.
libcamera: beautify V4L2Camera.cpp
libcamera: don't skip preview frames

Preparation for newer drop frame policy
libcamera: better skip preview frame policy
libcamera: allow to change ISO
libcamera: add image effects support
libcamera: add scene modes
libcamera: effects and whitebalance for BFC only
libcamera: add continuous focus mode
libcamera: fix maximum zoom level
libcamera: set parameters while switching from capture to video mode
libcamera: fix parameters initialization
libcamera: allow to change JPEG quality