[469c] Add into UnrealEd possibility render world with special grid textures useful for mapping

[SeriousBuggie]

Idea goes for check some checkbox, and in editor, in all modes, instead of original textures, start use special one.
Like this:

I think it must be additional option in context menu, like show paths:

since it can be used in few editor render modes. For example with light and without.

Such view very useful for place items, align brushes and so on.

[SeriousBuggie]

There examples of such textures and use of it: https://ut99.org/viewtopic.php?t=12515

[SeriousBuggie]

There can be different colors for such textures, Like 5 or 10. And it rotate over used brush for example.
And two modes - with all colored same, and colored differently.

[SeriousBuggie]

Grids from Berserker:






Grids.zip
Second variant:






TextureGrids.zip

[SeriousBuggie]

As additional use case:
It very useful for actor placement (pathing, inventory placement) on maps where actual texture is goes be grey, and cursor almost invisible on it.

Like this one:

There cursor black only because sshot tool make it such on real use there no way see cursor. It same color as surface.

[SeriousBuggie]

Possible implementation (Texture determined by TextureGrid.png in System folder):