Add support for IMX477 sensor in PiBayerArray class?

[AlecVercruysse]

Since the new HQ camera uses the IMX477 sensor, which outputs 12-bit color, the current PiBayerData class unfortunately throws errors relating to the fact that the v1 and v2 sensors output 10-bit color.

With this, it's also probably worth fixing the bug mentioned in #563, where the byte containing the low bits of the packed data is shifted too far left.

[xlla]

According to this document, only use adc 12 bit for full (4:3) normal 40 fps, else is 10 bit.