Previously we were not checking for the correct format support
to expose this extension. This change fixes that, and disables
the extension if we do not support the formats we need for our
implementation to function. This also adds an end2end test to
check each possible format that can be used with this extension.

Update GLES major version to 3 for TextureSampling perf benchmark

Bug: angleproject:4561
Change-Id: Ic81bb28f02f9f36e1bc83a8eea376169de9e7735
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2359482Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>