Support editing a control's class

[Bronstrom]

Description

As a user of the OSCAL Viewer/Editor, I would like to be able to edit the class of a control.

Acceptance Criteria

• The control class can be modified:
  • based on a pull-down list of known classes;
  • as well as edited raw for unknown classes.

Proposed Solution

No response

Additional Notes

No response

Implementation

• I can (or plan to) submit a pull request to implement this
• Implementing this may result in a breaking change

[brian-ruf-ezd]

There are both recognized and unrecognized classes. Recognized classes are managed in an enumerated list with both human-friendly and OSCAL-friendly values.