In certain cases (like chat quoting) we need to be able
to call the API with an async AJAX call before copying
the results to the clipboard. The only way to reliably
do this is by handing off the AJAX promise to a ClipboardItem.
This commit introduces a new clipboardCopyAsync function
to handle this, which will stand alongside the existing
clipboardCopy function which can be used when no AJAX
request is necessary.
Martin Brennan
0832cad803