Fix for #16771.

[jmdowns2]

Now insertCursorAtEndOfEachLineSelected works with multiple selections.

[msftclas]

Hi @jmdowns2, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, MSBOT;

[yajiex]

This can be simplified to let newSelections = selections.map(selection => this.getCursorsForSelection(selection, editor));