Hashes - Add parameter to prevent removing default values

[jokoho48]

When merged this pull request will:

• Adds a Parameter to CBA_fnc_createHash that prevents removing defaults from hashes.
  ref: CBA_fnc_hashSet deleting default values is ... just bad #1358 (comment)

[PabstMirror]

_hash = [[], nil, false] call CBA_fnc_hashCreate; 
[_hash, "A", nil] call CBA_fnc_hashSet;
[_hash] call CBA_fnc_hashKeys;

returns []

_hash = [[], 5, false] call CBA_fnc_hashCreate; 
[_hash, "B", 5] call CBA_fnc_hashSet;
[_hash, "B"] call CBA_fnc_hashRem;
[_hash] call CBA_fnc_hashKeys;

returns ["B"]