For yet unknown reasons, sometimes invalid mentions are inserted into the list, which will mess up all further messages. While finding those bugs is the better approach, these checks should also be useful.
Resolve https://invent.kde.org/network/neochat/-/issues/547
This patch attempts to add proxy config support to NeoChat so people could set a HTTP or Socks5 proxy for anonymity or privacy/censorship-circumvention reason.
Currently this will only allows setting proxy type, host and port (which should be usable for most of the cases). Settings in that page needs to be applied by clicking the Apply button so the proxy setting won't accidentally get changed.
Proxy is disabled (use System Default option) by default.
Use animated images in imageDelegate and FullScreenImage so that animated images can be viewed.
Note webp animated images don't work this is a bug with qt see https://bugreports.qt.io/browse/QTBUG-70245
Update the base item in the timeline container to be a column layout. This means that all the items can be laid out automatically without the need to set lots of manual settings and anchoring.
The overall height calculation for the delegate is vastly simplified (in fact it is removed) which deals with the fact that there were still instances where the manual calculation didn't work e.g. a delegate with a reaction followed by another message from the same user didn't give the correct bottom margin (see below)
before:

after:

This also improves upon the recently changed hover highlight behaviour. The previous patched moved it to cover the avatar as well as the bubble however it also covered the section and reaction when present which didn't look good. The highlight now only covers the avatar and bubble
before:

after:

This also cleans up some of the margins in both bubble and compact to ensure consistency.
Set max size to gridUnits * 30. The aim is to allow them to be generally bigger than bubble mode but not so huge that they take up the entire screen
BUG: 454878