Adding Events and Search implementation (serverHanlder)

[kqarryzada]

Downloading events from the server to the UI is still unimplemented. Additionally, the basic search that Jacob implemented needs to be added to the front end as well.

• [x] Fix bugs associated with creating a username from the app
• [x] Implement logout in ServerHandler to allow logging out in the UI
• [x] create PEvent
• [x] Implement method for displaying a user's photos
• [x] Implement method for posting to a specific event
• [x] Implement search in the front end in ServerHandler layer. Sends search term to server and returns list of results to the front end.
• [x] Implement event grabbing for UI in ServerHandler layer

[JesusLegaspy]

Fixed da create user bug. Header was missing from postJson