Fomantic-ui's action button syntax requires that the button is
the next sibling of the input it is attached to and that they
are both children of a div.action.
Fix#11375
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>
The choice regarding which forms should or should not trigger a warning
is subjective. I tried to be consistent and not warn about forms that:
- run an action, rather than edit data: search, send an email.
- delete data: a warning about losing data would be confusing
Note that forms on sign-in pages were already ignored (using a selector,
rather than an explicit class on the form element).
Fixes#3698.
