adds auto-complete support for other stacker.news users when withdrawing
to a lightning address
implemented via adding an optional `transformUser` prop to the `UserSuggest` and `InputUserSuggest`
components, which allows you to transform fetched user results before displaying in the suggestion
dropdown
this is used to transform a user nym to nym@stacker.news, the corresponding
lightning address
by default, `transformUser` is an identity fn aka no transformation
this change also clears suggestions when the surrounding input field is blurred, which
is a better UX IMO
6d3482a288