Added PrestoContext class.
Huge refactoring that wraps topic, type and view into PrestoContext instance.
Fixed assignment bug in PrestoContext.
Added null check in PrestoContext constructor.
validate-topic now uses the topic id of the topic view object, not the topic id from the request.
Now filtering out non EDIT_IN_VIEW views from Topic.views.
Removed PrestoType.readOnly, which is now defaulted down onto PrestoField.readOnly. Moved readOnlyMode to PrestoContext.isReadOnly.
Merge branch 'feature/presto-context' into develop