Update GL_ARM_shader_framebuffer_fetch token support These were missed during initial implementation because the target app doesn't use them, and there are no tests for vendor extensions. The implementation is basically a noop, but allows setting and querying state, unblocking apps. Also add a test that has basic usage. Test: FramebufferFetchES31.BasicTokenUsage_ARM Bug: b/269233744 Bug: angleproject:8025 Change-Id: Ic107150d4afd9c4c4984c58a1dafb1c18e608997 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4255965 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Cody Northrop <cnorthrop@google.com>