Clean up extra attributes set in `clipboard_button` helper

Context

The following discussion from !53224 (merged) should be addressed:

  • @pslaughter started a discussion:

    note (non-blocking): It seems to me that there's a lot of extraneous things we leave in this object we're passing to data (i.e. class and hide_tooltip). When we read these values, I think we intend to pop them out of the object so they don't end up written to the HTML as data attributes (i.e. data-class) 🤔

    This is a pre-existing problem, so it shouldn't block this MR but might be nice to clean up in a follow-up.

On .com, you'll notice clipboard buttons have weird data attributes because of this:

Screen_Shot_2021-03-08_at_2.38.04_PM

Investigation Notes

In the clipboard_button helper, we could probably just use .delete instead of reading the various keys so that the keys are also removed and not added to the element's data attributes.

Edited by Lee Tickett