GS/HW: Added new Half-Pixel Offset option Bilinear Scaled (Testing Only)

[refractionpcsx2]

Description of Changes

Adds a new HPO option Bilinear Scaled, which only affects bilinear draws where the gradient is of a reasonable amount (not too small)

Rationale behind Changes

Can be useful for games doing post bloom effects. So far it seems to work well with Yakuza 2 and Kingdom Hearts Final Mix with no other upscaling fixes required. Tekken 5 looks arguably better upscaled with the rendering fixes disabled, but there is still some lines.

Suggested Testing Steps

Test games which work well with HPO Normal (Vertex) but suffer from garbage around the edges of the screen, or the offset isn't quite enough/correct.

Not sure if I'm going to merge this yet or not, I want to gauge it's usefulness first.

Some shots at x8:

Yakuza 2:
HPO Normal:

Bilinear Scaled:

KH2:
HPO Normal + Round Sprite Full:

Bilinear Scaled:

Driving Emotion Type-S:
HPO Normal:

Bilinear Scaled:

[sinisterseed]

Not sure if I'm going to merge this yet or not, I want to gauge it's usefulness first.

Perhaps not the most useful comment to be seen in this PR, but I think another game that would benefit from this would be BloodRayne 2. A couple of months ago when I played those games, I noticed the same lines in BR2 as in the Yakuza screenshot.

Because most areas in the game are relatively dark, the lines weren't noticeable, but towards the end where some stages even set during daytime started showing up, they suddenly became extremely prominent. Unfortunately I no longer have these games to show what I'm talking about, but just my 0.02$ on this topic, since the merging of this PR is undecided.