R1:94c29007b694

Generalize rules for "workflow" sigil

Summary:
See discussion in D6130. Basically, all of these should activate workflow:

<a data-sigil="workflow" href="...">...</a>

<div data-sigil="workflow">
<a href="...">...</a>
</div>

<form data-sigil="workflow" action="...">...</form>

<div data-sigil="workflow">
<form action="...">...</form>
</div>

The only case where we don't want to activate workflow is this one:

<form data-sigil="workflow">
<a href="...">...</a>
</form>

Here…