fix(multi-select): reset selectedIds when clearing selection

[keehun]

Here I have a fix for issue #1831. I am unable to reproduce the issue (reproducible with master branch here) after applying this patch.

If there is a better way to handle initial state set from onMount(), I would love to implement a better solution. Please let me know.

[metonym]

Thanks for providing a clear repro and description. LGTM

[metonym]

Released in v0.81.1

[keehun]

I noticed another issue around setting initial state in onMount() where the checked items don't show at the top of the list when MultiSelect is focused for the first time. I'll create a repro and open another ticket (and hopefully a fix) when I have a bit of time, but wanted to leave that here before I forgot about it. (This is mostly a note for myself.)