Removed all the separate query functions and simply expose the internal
info structures.  This reduces the number of std::map/std::set operations
that were hidden behind the API.

Moved the validation tables for ES3 format combinations and effective
internal formats into validationES3.cpp so that formatutils.h only has
generic GL format queries.

BUG=angle:658

Change-Id: Ieb60d42b8eafcdb4f21dcbec130b39478ce5f7c5
Reviewed-on: https://chromium-review.googlesource.com/206835Reviewed-by: Nicolas Capens <capn@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>