gl.xml: TextureStorage extension 1D/3D entry points conditional, and EXT missing from desktop

There's two slight issues that may be present with gl.xml's information on GL_EXT_texture_storage (and also potentially some overlap with GL_ARB_texture_storage).

1) The EXT extension specifies:

> In particular, note that OpenGL ES 1.x/2.0 do not have proxy textures,
> 1D textures, or 3D textures, and thus only the TexStorage2DEXT
> entry point is required. If OES_texture_3D is supported, the
> TexStorage3DEXT entry point is also required.

The ARB spec is specified against OpenGL ES 1.0 and OpenGL ES 2.0, which do not have 1D/3D textures but I didn't see any mention of the conditional exposure. Seems like an oversight - in any case this information is missing from gl.xml that I saw.

2) The EXT extension is specified against OpenGL ES 1.0, OpenGL ES 2.0 or OpenGL 1.2 but gl.xml does not include it as a desktop GL extension. Conversely for ARB, it is also specified as OpenGL ES 1.0, OpenGL ES 2.0 or OpenGL 1.2, but gl.xml does not list it for gles APIs. Not sure if this is intentional.

@oddhack can you provide any clarification here? It was something we noticed when implementing an entry point loader via gl.xml.