Add support for custom fields in data compliance rules

[johanek]

Closes: #205

What's Changed

This proposed change allows you to validate custom fields by referencing them as cf_<custom_field_name in ComplianceError exceptions.

This PR is more of a proposal than a final solution — I’m not sure if this is the approach you’d prefer for solving the issue, but I wanted to share some working code and get your feedback.

To Do

• Explanation of Change(s)
• Added change log fragment(s) (for more information see the documentation)
• Unit, Integration Tests
• Documentation Updates (when adding/changing features)

[glennmatthews]

Conceptually this looks like a pretty reasonable and straightforward approach. Since this App has been inlined into Nautobot core for the upcoming 3.0 release of core, we'll want to make sure this enhancement gets ported over there as well once it's accepted and merged here.

[glennmatthews]

Good catch! We should probably (at least in core/3.0) change this from a CharField to a TextField for more capability/flexibility.

[johanek]

Conceptually this looks like a pretty reasonable and straightforward approach. Since this App has been inlined into Nautobot core for the upcoming 3.0 release of core, we'll want to make sure this enhancement gets ported over there as well once it's accepted and merged here.

Great! I also added the changelog entry and doc changes, is there anything else needed for this change?