Fix T74019 Eevee High Quality Normals causing pitch black faces

Was due to a mistake when removing previous code...

DRW: Fix facing reset when drawing with inverted camera

DRW: Support inverted view matrix

We detect the case where we need to invert the facing directly inside the
DRWView update and do the appropriate GL calls at draw time.

Fix T63047 Camera with negative scale works only in Cycles Rendered view
Fix T71352 Negative scale camera causes BLI_assert

DRW: New High Quality Normal & Tangent extract

This patch adds a dedicated path to extract 16bit normals instead of packing them into 10bits/comp.
The tangents are also packed to 10bits/comp if not using the new High Quality Normal option.

Fix T61024 Degraded texture shading on dense meshes

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D6614

GPU: Limit Mesa workaround to older version

GPU: Fix huge performance regression regarding instancing

Under some circumstances, MultiDrawIndirect was disabled to improve perf.
of average scene. But this conflicted with the normal instancing buffer
filling if only 1 or 2 instances were needed to fill the buffer. All
consecutive drawcalls could not be batched together and performance would
degrade rapidly.

This patch make my instance test scene go from 11fps back to 40fps where
it should have been.

EEVEE: Fix default material disappearing when SSRefraction is enabled

GPencil: Fix double rendering when using workbench as target engine

DRW: Fix wrong view transform used in solid mode if using workbench engine

Fix T73793 Walk navigation crosshair gets hidden behind objects

This is a bug that the recent refactor exposed. Some widgets were drawing
with alpha set to 0.