update AsyncView to work with swr's loading flag and support nullable…#17

SirCotare merged 4 commits intomainaboutbits/react-toolbox:mainfrom

ab-180-async-view-should-accept-an-isloading-flagaboutbits/react-toolbox:ab-180-async-view-should-accept-an-isloading-flagCopy head branch name to clipboard