[opengl] Check for unchecked GL errors before data is app-visible

App-visible data must not contain incorrect data caused by GL
errors. Errors returned by GL work lose the device, but when asserts
are disabled DAWN_GL_TRY doesn't call glGetError, so failed GL calls
go undetected and frontend state assuming their success (e.g. a
texture or buffer marked initialized after an upload or a lazy
clear) can expose uninitialized memory.

Rather than checking every GL call, check for pending GL errors
(CheckPendingErrorBeforeUserVisibleData) where data becomes visible
to the application: after Queue::Submit
and when exporting a shared fence (EndAccess). The
check after Submit also covers present.

DAWN_GL_TRY_ALWAYS_CHECK no longer
clears errors left by earlier unchecked calls, so they are reported
instead of silently dropped before reaching these checks.
This also covers buffer mapping.

Expected errors from requesting unsupported extensions (with
gl_force_es_31_and_no_extensions) are discarded where they are
generated.

With gl_force_es_31_and_no_extensions, only extensions listed in
GL_REQUESTABLE_EXTENSIONS_ANGLE are requested, so that requesting
unsupported extensions doesn't leave GL errors pending.

No measurable perf impact in dawn_perf_tests on Mesa radeonsi GLES
(UniformBufferUpdatePerf/UsageTrackingPerf, median -0.4%).

Bug: 536539561
Change-Id: I5e90c26662cbffa4a79d97e19627e7feed202388
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/351016
Commit-Queue: Shrek Shao <shrekshao@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>