We fixed the main issue of this form in CVE-2020-9444, but the audit
done at that time only included links found in rendered_markdown; this
change completes our audit for links with target=_blank anywhere in
the codebase.
* There is only one word inside the buttons and that too was wrapped
inside `span.text` which was unnecessary. This is removed. All
corresponding properties (font-size) are moved to `.button`.
* Since the only `a` inside image actions are these buttons, all
the properties are transfered to `.button`.
* Similarly, properties for `.icon` are moved to `.button` and it is
also removed from the template.
* Font size was redundant for `.icon`
* display property is moved
This should make it easier to find the templates that are actually
part of the core webapp, instead of having them all mixed together
with the portico pages.