performance: editor's graphics

[Editor]
- We were iterating over the same 9 maps (3x3 grid) 6 separate times for different layers/attributes. This fix consolidates the whole thing into a single pass.
- Add DrawAllMapAttributes() to consolidate 3 attribute draw calls
- Cached property lookups in DrawGridOverlay, DrawTransparentBorders, and DrawMapBorders to avoid repeated access
- Cache textures and property lookups
- Move DrawMapGrid lines outside nested loop, reduction in draw calls
- Reduce DrawMapBorders from 8 to 4 calls, pre-calculates values
- Optimized DrawTransparentBorders with texture caching and IsDisposed check
- Add view culling to skip off-screen rendering
- Removes unused imports and variables.

- panda's review (I)

Signed-off-by: Arufonsu <17498701+Arufonsu@users.noreply.github.com>

Author: Arufonsu