Minor diagonal decal adjustments

[Blackszedows]

About the PR

Adjusted diagonal decals i made a while ago (still not perfect).
Mainly:

• made the half-tile diagonal a bit wider to fit regular half-tile decal more (see pictures)
• same treatment to corner pieces (now they stick out a pixel or two when using them at corner of perpendicular decals , hence the "not perfect, but i didn't want to make 8-16 different decals that differ by a pixel or two)

Why / Balance

I'm not good at making sprites by a mile, hence figured i should fix what i can, if someone else wants to make modifications feel free to.

Media

Diagonal pieces 2x2 (the corner pieces are also there)
Before:

After:

Preview with a wall:

• I have added screenshots/videos to this PR showcasing its changes ingame, or this PR does not require an ingame showcase

🆑

• tweak: Adjusted the sprites for diagonal tile decals.

[github-actions]

RSI Diff Bot; head commit e3b639d merging into 956cbe8
This PR makes changes to 1 or more RSIs. Here is a summary of all changes:

Resources/Textures/Decals/Overlays/greyscalediagonal.rsi

State	Old	New	Status
tilediagonal			Modified
tilediagonal_corner			Modified
tilediagonal_corner_180			Modified
tilediagonal_corner_270			Modified
tilediagonal_corner_90			Modified
tilediagonal_flipped			Modified

[Blackszedows]

To note, i did check with a ship of mine that had previous decals , and there shouldn't be any conflicts. Shouldn't.