* Add norm16 format info for OpenGL backend
* Add validation for newly introduced norm16 formats
* Fix some logic of texture tests

Bug: chromium:1000354, angleproject:1365
Change-Id: Ie6d6e5e276da4df4b7c667be28d324d4976b35ec
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1902720Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shrek Shao <shrekshao@google.com>
Commit-Queue: Shrek Shao <shrekshao@google.com>