DNM: CoreModularization for DynamoRevit

This makes DynamoRevit compatible with the changes coming in from the DynamoCore Modularization pull request: https://github.com/DynamoDS/Dynamo/pull/3389

#### Reviewers
* [ ] @Randy-Ma 
* [ ] @ikeough 
* [ ] @lukechurch 
* [ ] @pboyer (Make sure this works with your Core Separation stuff)
`RevitNodeModel` is now completely empty and can be removed.