Support more formats for x11 backend

[i509VCB]

At the moment only little endian Argb8888 and Xrgb8888 are supported.

We probably want to support big endian forms of these pixel formats along with some other formats, such as RGBA10_10_10_2 in little and big endian.

I imagine there are some other common formats we want to support, do comment if I have forgotten some of them.

Regarding code changes, we need to find the proper bpp and depths corresponding to the format.

[Ben2917]

Hello,

I'd like to make this improvement as my first contribution to the project if this would still be valuable. I've had a look around in the x11 backend so I've now got an idea where the changes should be made.