* Add a binary cache for compiled shaders using glProgramBinary

* Add additional sanity checking to shader binary save and load, hook up cache clear and menu option

* Fix default init of shader cache data struct and clear gl errors before glGetError calls

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Co-authored-by: RunitaiLinden <davep@lindenlab.com>

SL-19655 Remove concept of "low priority" updates (RenderDebugGLSession assertion stomping pass).  Remove a couple unused debug settings and related code.

following promotion of DRTVWR-577

SL-19674 Disable "Blinn-Phong" when a PBR material is applied to make it clear that those buttons are inoperable until you remove the PBR material.

SL-19709 Fix for fullbright shiny not factoring out exposure and flickering fullbright alpha.  Incidental decruft.

SL-19710 Fix for deadlock in LLPerfStats.  Move General thread initialization to earlier in session (unrelated).

SL-19236: Fix HUDs not rendering when transparent water graphics setting is off

SL-19656 Remove LLPerfStats thread and fold into General thread.  Hook avatar GPU time into LLPerfStats.  Incidental decruft.

SL-19690: Follow up on Rye Mutt's fix for shutdown crashes.

BUG-233797/233798 - fix blackout when u/w fog_density < 0 

SL-19644: De-virtualize pushBatch

Rather than continuing to propagate try/catch (Closed)
(aka LLThreadSafeQueueInterrupt) constructs through the code base, make
WorkQueueBase::post() return bool indicating success (i.e. ! isClosed()).
This obviates postIfOpen(), which no one was using anyway.

In effect, postIfOpen() is renamed post(), bypassing the exception when
isClosed().

Review existing try/catch blocks of that sort, changing to test for post()
returning false.

Fix exceptions during shutdown causing early program termination

Fix LLThreadSafeQueueInterrupt in WorkQueueBase::postTo during shutdown by catching and returning false

Bump still uses its own pushBumpBatch function - OK, works the same as
before.

enable github actions mac nightly builds