Rebuild Authentication

[jannaahs]

The used library was last updated 5 years ago and is not developed anymore.

Also middlewares can be used.

[knoxfighter]

• [x] Login
• [x] Redirect after login
• [x] Logout
• [x] Fix error after Logout
• [x] Check login status with middleware
• [x] Fix websocket connection
• [x] List users
• [x] Add user
• [x] Remove user
• [x] Change password
• [x] Error messaging (All errors are just moved, but nothing is printed (backendside))
• [x] Update readme/wiki and dockerfiles to use sqfile.db instead of auth.leveldb
• [x] When the cookieEncryptionKey is changed all current cookies are invalid and a login is not longer possible (Error 500)