Enable some more extensions and fix failures that arise from it

This series enables tessellation, geometry shaders, and additional texture sampling, and also fixes some shader issues that came up with the newly enabled tests. One could probably apply it as is, or wait until I've fixed the newly arising failures. I'm a bit unsure about the GLSLVersion=400 part though.

thanks for any comments.

Currently the series regresses dEQP-GLES31.functional.copy_image. tests with srgb8_alpha8_etc2 The offending patch adding VIRGL_FORMAT_B8G8R8A8_SRGB was that removed, mesa/gallium is actually using the wrong tests since mesa/st:71867a0a61ce The patch to fix this on the mesa side has landed

I think this now okay to be merged.