Implement randomkey command

[danielealbano]

This PR implements the RANDOMKEY command.

It refactors the hashtable op get key function to return a copy of the key from the hashtable and to ensure that the copy is actually valid implementing a 2-phase verification.

The PR also includes the tests for the new command and a minor improvement to the DBSIZE command

[codecov]

Codecov Report

Base: 80.84% // Head: 80.87% // Increases project coverage by +0.04% 🎉

Coverage data is based on head (66778f3) compared to base (93246b1).
Patch coverage: 86.36% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #202      +/-   ##
==========================================
+ Coverage   80.84%   80.87%   +0.04%     
==========================================
  Files         129      131       +2     
  Lines        7760     7801      +41     
==========================================
+ Hits         6273     6309      +36     
- Misses       1487     1492       +5     

Impacted Files	Coverage Δ
...ta_structures/hashtable/mcmp/hashtable_op_delete.c	100.00% <ø> (ø)
...uctures/hashtable/mcmp/hashtable_support_op_arch.c	93.87% <ø> (ø)
...a_structures/hashtable/mcmp/hashtable_op_get_key.c	82.35% <76.92%> (-8.56%)	⬇️
...tures/hashtable/mcmp/hashtable_op_get_random_key.c	100.00% <100.00%> (ø)
...ule/redis/command/module_redis_command_randomkey.c	100.00% <100.00%> (ø)
src/storage/db/storage_db.c	63.71% <100.00%> (+0.42%)	⬆️

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