🧹 Move TT outside of Engine: independent class, instantiated at top level

[eduherminio]

PR discarded due to non-deterministic bench bug (#1182, #1181), new branch and PR will be created

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73c5abe

Non-deterministic bench error though, probably related to passing around a class with a pinned object.
That is, when executing the binary with "bench" argument, results (node count) aren't always the same

Test  | refactor/tt-outside-of-engine-2-class-wrapper
Elo   | 3.95 +- 7.33 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=32MB
LLR   | 1.23 (-2.25, 2.89) [-5.00, 0.00]
Games | 3344: +927 -889 =1528
Penta | [67, 356, 792, 386, 71]
https://openbench.lynx-chess.com/test/908/