Support adding/removing metadata locations

[Bronstrom]

Description

As a catalog author, I want to add/remove locations in regard to metadata.

Acceptance Criteria

• Additional locations can be added
• locations can be removed
• location metadata additions/removals are supported correctly. For more information about each location metadata see: https://pages.nist.gov/OSCAL/reference/latest/catalog/xml-reference/#/catalog/metadata/location
• Full REST API support exist for these new routes

Proposed Solution

No response

Additional Notes

Please note that some location metadata can only have none of a certain element or only one of a certain element [0 or 1], while others can have as many as desired [0 to ∞]. Also several location metadata may have additional metadata underneath it (an address' addr-line) - this should also have addition/removal support as well.

Implementation

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

[Bronstrom]

Depends on #698