Add New Canon R6MKIII

**Is your feature request related to a problem? Please describe.**
Have an easy way to add new cameras as the come out

**Describe the solution you'd like**
As per Beta 3 notes --> Support CANON EOS R series cameras (EOS R, R3, R5, R6, R6m2, R7, R10, RP) by LibRaw.  I'd love to see the Canon R6MKIII added.  
**Describe alternatives you've considered**
N/A

**Additional context**
N/A
