one thing could for whatever reason not be avoided: Even though the
processors of the caches inside WriteProxy are initialized, they somehow
get "de-initialized" and have to be initialized again...
These are:
* different size of addContact- and SettingsButton
* default icons in light mode for users and groups (even though they are
currently just the version used in dark mode)
* wrong preferred size of unnamed "Login" label in LoginScene
* unopenable LoginScene for some OS (Debian)
* white screen when the current scene is switched
Additionally cleaned up code a bit in MessageControl and
LoginScene(.java)
Common
* Replace LocalDateTime with Instant everywhere
Client
* Display message creation date with system time zone in MessageControl
* LocalDB#users now strictly contains Users
* lastSync time stamp in LocalDB (saved per user)
* isOnline parameter in save function (lastSync updated if true)
* lastSync time stamp in LoginCredentials
* No ClientConfig#getLoginCredentials because of missing information,
moved to LoginScene
* Pass LocalDB#lastSync to LoginCredentials in LoginScene
Server
* Explicit lastSync parameter for
PersistenceManager#getPending(Group)Messages
This sends the correct time stamp to the server, however the JPQL
queries have yet to be adjusted.