[Megathread] Drag & drop on the '+' button

[zadjii-msft]

[original issue: #10073] [original pr: #10160]

### Tasks
* [x] #10721
* [x] #10722
* [x] #10723
* [ ] #10724

[zadjii-msft]

@fossdd You'll be happy to know that it's already been implemented in #10160 (as the OP describes).

The best way to show support for a feature is by hitting the 👍 button on this issue

That way, you avoid unnecessarily pinging everyone following this thread. Thanks!