When clicking a file in FolderView, we should ask for whether to open or run a script depending on user settings.
This is what Dolphin does.

BUG: 375793
FIXED-IN: 5.8.6

Created an .sh file, clicked it in FolderView, got a prompt. Selected multiple .sh files got a prompt for each one of them.

I just noticed that for multiple items Dolphin actually does

KFileItemActions fileItemActions(this);
fileItemActions.runPreferredApplications(items, QString());

instead of going through KRun, ie. in Dolphin selecting two script files and hitting return will actually open them in Kate rather than execute them both. This needs to be addressed separately.

This particular patch only applies to 5.9 branch since in 5.8 we didn't have execution of multiple files, (updated the patch now) let's make a fix for 5.8 and then also address the runPreferredApplications thing for 5.9 and then we have everything amazing.