DO NOT MERGE: Implemented new in-canvas view buttons

Various view manipulation ```DelegateCommand``` objects are merged from ```WorkspaceViewModel``` into ```DynamoViewModel``` because they do not need to be duplicated. The actual implementations of these commands now resurface from ```WorkspaceViewModel``` as internal methods (e.g. ```FitViewInternal```) that can be called by the actual commands in ```DynamoViewModel```.

The following changes are mostly surrounding this merge of commands.