Add an option to WBL General Settings to allow Teachers to just view events that they created

There is currently an option called Teachers Access Only WBL Experiences They Created but this applies to both student-based experiences and events. We should make this two separate settings for each so schools can refine how this works. Some would like teachers to have the WBL Observer role where they can see student-based experiences that coordinators created for their students but only see events that they create.

For instance, teachers have no need to see field trips or guest speakers from other teachers.