Add an utility function which checks if a Python value is a valid standard value

Some checks:

• a value is one of container types
• all inner data should be of data types
• it has metadata attribute
• call metadata validation on the value to check if structure inside metadata matches structure of the value

This might be relatively heavy operation so not sure if it should be called automatically, but it could be used by TA2 systems and validators when evaluating primitives.