Support tabbing through controls in modals, popovers, and selects

I rebased the work that @thangdinh did, as he will be unable to work on this for a while. Not very familiar with the code, so hoping that someone else is.

@cyril-sf @azirbel @Dylnuge @jpriceAddepar 
Yeah, I was puzzled about that part and decided to make that change. If you know a better solution, please show me. Much appreciate. Thanks.