If an Entity or Attribute is not included, don't allow it to be mapped to or from. #858
Description
Is your feature request related to a problem? Please describe.
When on the mapping tab in the MDR, if I try to map something that isn't included in the data model, it doesn't provide an error to the user, the mapping just doesn't connect. It does create a 404 in the network tab.
Describe the solution you'd like
If an Entity or Attribute is not included in the data model (by selecting 'inc' in the data models tab), then it should not have the dot to allow for it to be connected to or from in the mappings tab. This could also be handled by making the dot an 'X' or some other indicator that the Entity or Attribute is in the data model, but not included and therefore it is not mappable.
Describe alternatives you've considered
An alternative is to hide the non-included Entity or Attribute completely from the mappings tab, but I think this would reduce visibility into those items. By leaving it visable and indicating in another way that it's not mappable (no dot to link or an x instead of a dot) it allows users to see the full data model.