FFV1 support for read and write

This is a very quality lossless codec that is used to archive video.
The codec is open sourced and seems has no known patent limitations.

Thank you for adding it to Resolve.

Could you also add a 9-bit in additional?

The idea is to keep sources for 8-bit videos without a grain. 10-bit encoding requires a bit more data to store. 9-bit quality is a good solution to get more quality for low-quality graded 8-bit images with a less storage space.

9-bit encoding is supported by FFmpeg. Currently Resolve can read these files, but a Write preset may be a good idea.