messaging/Notifications

[GnarLito]

Adding message support to the API.
What does this involve:

• adding classes for Messages and MessagesGroups
• adding support to send, update, leave POSTS

[GnarLito]

Current problem:
message only contains the userId and not the username.

There needs to be a way to add userIds to the user class or a translation from group users and message user

[GnarLito]

Kinda forgot to add notification class support woops