Multi-selection pasting is broken for multi-cursor

[munael]

Repro

1. Make multiple selections. E.g. by Ctrl-d.
2. Copy by y.
3. Make the same number of cursors as selections in (1) elsewhere.
4. p to paste.

The text from the selections is first concatenated then pasted at every position with a cursor. While VSCode would natively split the buffer up across the selections.