Rely on read tx for the hashtable consistency

[danielealbano]

Now that every operation on the hashtable is always behind a read or write transaction, it's not necessary to have to rely on a tricky logic and memory fences to ensure that a read will never cause an issue if a write changes something as they will never run in parallel.

The PR drops the memory fences, introduces some minor optimizations now that reads are consistent and clean up a lot of unnecessary logging.

The PR also contains a minor fix for a build warning when building C++ code (e.g. benchmarks or tests) and the necessary changes to update the set benchmark for the hashtable to the new paradigm implemented.

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Files	Coverage Δ
...hashtable/mcmp/hashtable_support_hash_search_avx.h	100.00% <100.00%> (ø)
...ashtable/mcmp/hashtable_support_hash_search_avx2.h	100.00% <100.00%> (ø)
...ashtable/mcmp/hashtable_support_hash_search_loop.h	100.00% <100.00%> (ø)
src/thread.h	100.00% <ø> (ø)
src/transaction.h	95.00% <100.00%> (+0.13%)	⬆️
src/storage/db/storage_db.c	59.80% <66.67%> (+0.10%)	⬆️
...uctures/hashtable/mcmp/hashtable_support_op_arch.c	92.81% <87.50%> (-0.23%)	⬇️

... and 1 file with indirect coverage changes

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