Provide OpenGL ES 3.1 as an extension/context

[wizgrav]

It would be great to have an extension/context providing OpenGL ES 3.1 features like compute shaders and indirect draw/dispatch on platforms that support it through ANGLE which is the majority of devices out there.

The discovery for the features that can be enabled has already been done during the drafting of WebGL2-Compute.

https://registry.khronos.org/webgl/specs/latest/2.0-compute/

Implementing it should be very easy at least on Chromium as they already support it internally through a build time flag for testing.

Would be more than happy to provide a patch to add the missing idl