Add a macro to check for GL errors after each GL call to catch errors as they
happen even if the debug callbacks are unavailable.  GL errors are only checked
when asserts are enabled unless explicitly requested with the
ANGLE_GL_TRY_ALWAYS_CHECK macro to verify GL calls that may allocate memory.

Updated TextureGL to use the macro.

BUG=angleproject:3020

Change-Id: I7678b204899e940824b010ab4be7e7f159bee6de
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1764476Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Commit-Queue: Geoff Lang <geofflang@chromium.org>