opengl: Regenerate code with ES 3.1 and new extensions

Enable ES 3.1 generation in glgen.py, and regenerate everything to add
support for that as well as these new extensions in the registry:
- EXT_copy_image
- EXT_draw_buffers_indexed
- EXT_geometry_shader
- EXT_gpu_shader5
- EXT_primitive_bounding_box
- EXT_shader_implicit_conversions
- EXT_shader_io_blocks
- EXT_tessellation_shader
- EXT_texture_border_clamp
- EXT_texture_buffer
- EXT_texture_cube_map_array
- EXT_texture_view

Bug: 15028495
Change-Id: I35acb473cba2433b9aeb95d1b8bfbdcfadf22532