EEVEE: Depth of Field: Improves jittered camera sampling pattern

Jittered camera now uses an hexaweb sampling pattern that covers the
bokeh area better and faster than previous pseudo random solution.

The downside is that we need to change the sample count based on the
number of rings to fill. We increase the number of samples just to fill
the largest ring.

EEVEE: Depth of Field: Improves denoise filter

This improve spatial stability by only clamping down pixels that
are too bright (fixing the issue of bright pixels inflating).

Also use the full 3x3 region to avoid cross shape patterns.

Cleanup: Fix formating

Merge branch 'master' into eevee-dof-refactor

EEVEE: Depth of field: Cleanup eevee_shaders interface

EEVEE: Depth of field: Remove studiolight related changes

EEVEE: Depth of field: Fix typo and wrong ownership

EEVEE: Depth of field: Move versioning code to versioning_290.c

EEVEE: Depth of field: Add slight defocus bokeh shape foreground flip

EEVEE: Depth of field: Fix bokeh shape rotation inverted

This was comming from that the rotation was based on foreground
shape which is now the one we invert.

EEVEE: Depth of field: Fix bokeh shape not inverted for scatter

The wrong vector was negated.

EEVEE: Depth of field: Fix incorrect prediction for holefill tiles

Holefill is only needed if having foreground elements in the tile.

EEVEE: Depth of field: Improve slight defocus opacity estimation

This correct the opacity estimate (for some reason the number of samples
returned by dof_gather_total_sample_count is wrong and ring_count needs
to be incremented).

Also adds a bias towards the focused area to improve the transition to
fully opaque.

EEVEE: Depth of field: Bleed more background over in-focus area

Improves water-tightness.

EEVEE: Depth of field: Fix tile prediction and fast gather threshold

Tile prediction wasn't using the correct threshold and fast gathering
wasn't taking layer weight into consideration.

Both were making tilling artifacts.

EEVEE: Depth Of Field: Fix jittered dof breaking screenspace effects

This was the case in perspective view. Seems like changing the projmat
origin was the issue. Instead we rely on window_translate_m4 to skew
the matrix and jitter the viewmat position to offset the origin.

EEVEE: Depth Of Field: Flip bokeh shape on foreground.

This is to mimic optical phenomenon and also match jittered DOF.

Merge branch 'master' into eevee-dof-refactor

EEVEE: Depth Of Field: UI: Change Jitter option name & tooltip

EEVEE: Depth Of Field: Add minimal overblur radius

This makes jittered Dof much easier to use as it scales itself
with the number of samples.