🧹 Move TT outside of Engine: instantiated at top level (Program.cs)

[eduherminio]

Simplified version of #1184.
Wrapper approach is preferred, but I considered it was worth testing the concept before going deeper into wrapper/no wrapper/which wrapper/where.

GC set to false just for testing purposes

Test  | refactor/tt-outside-of-engine-3-basic
Elo   | 2.24 +- 3.16 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=32MB
LLR   | 2.91 (-2.25, 2.89) [-3.00, 1.00]
Games | 19842: +5593 -5465 =8784
Penta | [469, 2264, 4360, 2326, 502]
https://openbench.lynx-chess.com/test/956/