add storage dataclass + refactor of PgDatabaseInspector

• introduce GpfStorage dataclass

• use new class in GpfStoredData

  • add new property database
  • add method to check if database is associated to stored data

• move PgDatabase definition from GpfOrchestratorParameters to GpfStorage

  • refactor database definition to use new GpfStoredData properties
  • add get_database_from_stored_data to add user and password from global_variables

• add setter for output_stored_data in GpfOrchestratorParameters

• refactor PgDatabaseInspector to add method to update stored data with database information