Create Model Extension Definition Resource Validation Rules

Validation rules need to be created for when MEDs are saved. These rules will run when a build is run. We may need to create our own builder also. Validation rules should exist for at least the following:

1. when a model contains a different version of a MED than the one in the registry (high priority)
2. when a model contains a MED that is not found in the registry (high priority)
3. move current problem marker creation out of MED Editor and into a validation rule (high priority)
3. when a model object has an extension property but does not have the MED stored in its model (low priority)
4. when a model object has an extension property that is not found in the corresponding MED (low priority)
5. any others that are needed