Review Ego Swagger API Message Enhancements

[b-f-chan]

Review Ego swagger API message enhancements here:
https://wiki.oicr.on.ca/display/OV/API+Messaging+Enhancements#APIMessagingEnhancements-Ego

(1) Review these groups:

• API Key endpoints
• Application endpoints
• Group endpoints
• Policy endpoints
• Transaction endpoints - For this group specifically, I understand what they do, but I could not get them to work in testing
• User endpoints

(2) Auth endpoints may need to wait until @b-f-chan returns so @anncatton can show me how to test and use in real-time, not documented yet.

A lot of descriptions I updated or added through my understanding by testing the endpoints, but may not be 100% correct or accurate, so please review and suggest any changes needed, thank you!