*  (confetti) message support.  Thanks @LorenDB !

fixes #400
fixes #1136

The reply pagination logic is a bit weird rn though.

* First draft of unread line feature.

* Minor visual fix.

* Removed unnecessary ternary operator.

* Extended unread line functionality to work on minimised window or focusing another window.

* Fix for unread line not showing when last read message is hidden.

* Minor performance improvement. Fix for misbehaving event2order DB at application start.

* Fix for possible performance issues when user has joined a large number of rooms.

* Fix for breaking macos and clazy builds.

* Changed on windows focus function to refresh unread line if room is unread.

* Unread line is removed when user sends a message.

* Linting.

* Fixed unread line to work in standalone room windows.

* Switch isRoomUnread for index 0.

* Merged try/catch blocks.

* Fix for crash on opening a room invite.

* Call fullyReadEventId function when used instead of storing it and passing it through.

* Function that was meant to sync the unread line was relying on an async function, oops.

* Linting again.

* More linting...

* Minor changes.

This helps with #1065, although I think making sure the message input box gets focus by default would be worthwhile.

* Added escape handler for uploads

* Update MessageView.qml

Changed if-else conditions to handle only one escape at a time

* Use advanceWidth to get the with of the original text

Co-authored-by: Nicolas Werner <nicolas.werner@hotmail.de>

# Previous commits:
#   5949173b Add function to force focus on InputDialog input field
#   9482ac4e Allow explicit selection of SSO method
#   ab05e2d8 Mobile message input (#962)
#   12a6da01 If you replace the txn id, replace a string the length of the txn id...

* making userName_ an AbstractButton should make it play nicely with the ListView

* make Avatar an AbstractButton

* make userName_ in Reply.qml an AbstractButton

* use alias for avatar background color and fix margin of username in reply

It seems that you need to manually destroy created objects... Great...

fixes #898

That way we can autohide the scollbar if needed, it should fix some
jumping issues, it makes it possible to flick on mobile, etc.

Some related bugs:

https://bugreports.qt.io/browse/QTBUG-75223
https://bugreports.qt.io/browse/QTBUG-44902

fixes #941