Fix namespace squatting in MR

[adamdossa]

1. You need to be owner to register (and verify) modules until customModulesAllowed is switched on in the feature registry.

2. Cleaned getters for MR - we now have:

    function getTagsByTypeAndToken(uint8 _moduleType, address _securityToken) external view returns(bytes32[], address[]);
    function getTagsByType(uint8 _moduleType) external view returns(bytes32[], address[]);
    function getModulesByType(uint8 _moduleType) external view returns(address[]);
    function getModulesByTypeAndToken(uint8 _moduleType, address _securityToken) external view returns (address[]);

3. Removed - tags looked up directly in module factories:
   addTagsByModuleType
removeTagsByModuleType

[pabloruiz55]

Looks good now, @satyamakgec please review and approve if everything looks ok.