Default External Parameters Do Not Enforce Defaults

[LeStarch]

External parameters allow default value specifications:

    external param SECTION_CONFIGS: SectionConfigs default TELEMETRY_SECTION_DEFAULTS

However, the loadParameters function generated does not supply the default value when it fails to load from the database:

    // Get parameter SECTION_CONFIGS
    param_valid = this->m_paramGetOut_OutputPort[0].invoke(
      _id,
      _buff
    );

    // If there was a deserialization issue, mark it invalid
    if (param_valid == Fw::ParamValid::VALID) {
      // Pass the local ID to the delegate
      constexpr FwPrmIdType _localId = PARAMID_SECTION_CONFIGS;

      FW_ASSERT(this->paramDelegatePtr != nullptr);
      // Call the delegate deserialize function for m_SECTION_CONFIGS
      _stat = this->paramDelegatePtr->deserializeParam(_baseId, _localId, param_valid, _buff);
      if (_stat != Fw::FW_SERIALIZE_OK) {
        param_valid = Fw::ParamValid::INVALID;
      }
    }
    else {
      param_valid = Fw::ParamValid::INVALID;  // <------- Here the database failed to load. However, no call to `deserializeParam` with a default value was supplied
    }

Since default is allowed with external it seems that the default value should be supplied to ensure that the default is set.

[bocchino]

Blocked on merging #982, because of code refactoring on that branch.

[LeStarch]

CCB: On failure to load from prmDb, ask external managment to handle the default value provided by us.