This implements a new JobViewV3 which uses extensible variant maps rather than individual function calls, allowing for compression of calls and extensibility.
The new API uses infoMessage correctly as a state message, e.g. "Connecting to host" rather than mixing it with the "Copying..." heading.
It also supports an "immediate" flag that the caller can use to indicate progress should be immediately shown, so in cases where the user is likely to want to use the file afterwards (e.g. download through p-b-i or receiving a file through KDE Connect) a job popup is shown even for small/short transfers.

This has to go into 5.16 branch as I implemented the interface in 5.16 but it is defunct, so when we ever start using it in KIO it will see the interface but it will not work.

Used a WIP branch of kjobwidgets/kio and been using the new API without a hitch.