Refactor RDBMS functions for catching SQL exceptions

Currently, we are using logic in the code to handle constraints in the DB. This is not best practice, example:

void RdbmsDiskSystemCatalogue::createDiskSystem(const common::dataStructures::SecurityIdentity &admin,
  const std::string &name, const std::string &diskInstanceName, const std::string &diskInstanceSpaceName,
  const std::string &fileRegexp, const uint64_t targetedFreeSpace, const time_t sleepTime, const std::string &comment) {
  try {
    if(name.empty()) {
      throw UserSpecifiedAnEmptyStringDiskSystemName("Cannot create disk system because the name is an empty string");
    }

We should instead let the database handle the exception throwing. Especially for:

• Unique constraints
• Foreign key constraints