When performing bulk dismissal in Unread and New views, the dismiss button stays at the top of the UI. Because of this we want to provide the dismiss action also in the "sticky" menu that's always in view, even when scrolling a long list of topics.
The bulk actions menu for topics has multiple options to work
with tags on topics (append, replace, remove). Our tagging system
along with categories allows for some complicated tag restrictions
to be applied via tag groups. This was a problem for the topic bulk
actions because you couldn't append restricted tags to topics.
This commit allows restricted tags to be used in bulk tagging actions
as long as all selected topics are for a sole category. The category
information will be shown in the modal, and the category ID is used
for the tag search.
