MAGN-4696 Remove old DynamoRevitTests that duplicate those in RevitNodeTests (DO NOT MERGE)

http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4696

This pull request removes old tests in DynamoRevitTests which are now replaced with unit tests in RevitNodeTests. System tests in DynamoRevitTests, such as those in SampleTests, DocumentTests, and SelectionTests were not removed. DynamoRevitTests will be for System tests in the future.

Reviewers:
- [ ] @riteshchandawar 

Merges Required:
- [ ] Revit2015