Clarification of usage for Session Presented and Session Established CAEP Events

[iamseanodentity]

What: Add clarification and example use cases outlining examples of usage of these events.

Where: Session Established

Session Presented

Why: The verbiage needs to be a bit more concise and clear on usage.

Proposal: Add a use case section to both sections 3.6 and 3.7 as 3.6.3 and 3.7.3, respectively and update the reason bullet points for both events.

[iamseanodentity]

No New sub sections just introduce more text in the body of the event and additional bullet points. @FragLegs for @iamseanodentity to do.