Respect the editor.autoIndent option when pasting

:rotating_light: WIP :rotating_light: 

Closes #1407

* [x] respect `editor.autoIndent` option when pasting
* [ ] don't auto-indent when pasting after non-whitespace characters
* [ ] add config option to preserve leading whitespace before cursor when pasting with auto-indent on
* [ ] figure out a good name for said option