DriverDetails: Add broken dual source blending bug to MoltenVK on Intel GPUs

[OatmealDome]

The Metal driver on Intel GPUs appears to have a bug where if ocol1 is present in the fragment shader and dual source blending is enabled, entire primitives will not be written to the depth buffer if any fragment is discarded.

This causes many games to exhibit odd layering issues that look similar to Z-fighting. The problem is especially pronounced in the Paper Mario games, where it affects basically every sprite-like object.

Apparently, a similar-ish bug also involving ocol1 is also present in the OpenGL driver: see #4402, #6219.

Fixes https://bugs.dolphin-emu.org/issues/12137 and https://bugs.dolphin-emu.org/issues/12317.

(I'm not very experienced in graphics programming, so the comments / explanation might be wrong. Feel free to correct.)

Depth buffer comparison

Dual source blending enabled:

Dual source blending disabled:

[JMC47]

All of this sounds pretty logical based on the bugs we've seen.

[OatmealDome]

Rebased and modified to be more in line with how OpenGL handles BUG_BROKEN_DUAL_SOURCE_BLENDING (i.e. only enable dual source blending when necessary to emulate destination alpha).