[clipboard-] speed up setcol-clipboard and make it async

[midichef]

setcol-clipboard is very slow for large numbers of rows. It also freezes the display while it runs.

To see the slowness: do seq 1000111 |vd - then paste a column of a million rows via gs gzy za newcol gzp. On my system it processes a few thousand rows per second.

This PR makes setcol-clipboard about 100x faster. It also adds the @asyncthread decorator to setValuesTyped() (like setValues()) so the screen can continue to update while setValuesTyped() runs.

[saulpw]

I'm surprised that this is a 100x speedup, but it does simplify the code, and there's already the cycle() in setValuesTyped. Thanks for finding/fixing it.