We were already doing that when deleting content blocks from the index
page, and we also ask for confirmation in almost every page in the admin
section.
We were already using button to destroy content blocks from the content
blocks index.
As mentioned in commits 5311daadf and bb958daf0, using links combined
with JavaScript to generate POST (or, in this case, DELETE) requests to
the server has a few issues.
This way we can simplify the code and don't have to rely on `.try`
statements which are confusing and so we don't allow them in the
`Rails/SafeNavigation` Rubocop rule.
