Enhancements to multi-selection

[qstokkink]

Discussed in #8359

^{Originally posted by balupton December 27, 2024}

• ability to use cmd+click to additionally select the clicked item (current shift+click behaviour)
• ability to use shift+click to additionally select all between the last clicked item and the newly clicked item (missing functionality)
• do not select text when cmd/shift+clicking, the text selection makes it seem that it does not work, should be cursor: pointer !important; user-select: none;

in this video, I've applied the stylesheet change, and demonstrating how shift+click doesn't select in-between

2025-01-07.01-04-03.mov