|  | Referentials#show has a button "Purger" that isn't a link. Instead, it's
a `<button>` element that opens a modal.
Previously, we only knew how to put `Link`s in the `#action_links`, and
only these could then be rendered in the header bar as buttons.
This change allows us to accept non-Link objects. Since the button is
rather simple, I decided to create a simple `HTMLElement` class to
represent it and output it in the resulting HTML. The class uses the
`#content_tag` `ActionView` helper to render the final HTML.
Update "referentials/show.html.slim" to output the button correctly in
addition to the normal links.
Update `TableBuilderHelper#build_links` to not add anything that's not a
`Link` to the gear menu. This allows us to display the "Purger" button
on the Referentials#show page but not in the table on Workbenches#show.
Refs #3479 |