Add context menu for results
This offers additional actions, such as "copy path", "open with", the service actions (share, send to device, etc), and others to results.
For applications, their jump list actions, if any, are presented.
Most of it is taken from notifications, which does the same for screenshots. Especially, the ability to "Open With" I miss a lot in KRunner.
The menu can be opened by the button, by right-clicking, or the "menu" key on the keyboard. (My Thinkpad sadly doesn't have that, so I cannot test whether that opens the menu as it should
(We can probably forgo the "Open Containing Folder" entry? as that is usually provided by the runner anyway)
Makes me wonder if we should put a shared component like this somewhere but I think we can't depend on p-w from here as p-w depends on us already..