Memory Optimization & Tile Caching

[SebiSebas1524]

Description:
Keep tiles in memory so we don't have to reload them constantly. But also don't keep everything forever because that'll blow up memory usage. Need to figure out what tiles to throw away when we're running low on space.
Acceptance Criteria:

• Doesn't use all your RAM
• Threads don't deadlock trying to access tiles
• Old tiles get removed when needed
• Can handle lots of tiles