(1.16) Cleanup and optimise AI

[PaintNinja]

• Add missing @Overrides
• Improved style consistency
• Implemented a cache for lists that call the expensive AABB to improve performance
  • This exploits the likelihood that players won't move far within 0.05s (1 tick), instead caching and reusing the calculated list for up-to 4 ticks
  • The cache is updated every 4th tick and cleared when no longer in use to prevent stale data.
• Optimised maths code, marked primitives as final where appropriate
• Reduced unnecessary calculations and checks, commented out dead code
• Replaced new Random() with ThreadLocalRandom.current()
• Changed size checks from slotlist.size() >= 1 to the faster and clearer slotlist.isEmpty()

[TheBv]

Looks good :)
Thanks for your work!