#41341

spacing updates to expander button
sub-title fixes

[ci skip]

`breadcrumb_title` is then overriden when needed

Earlier, this was part of another MR, but that got split. Didn't pick
that commit, as there were many merge conflicts. Vim macros seemed faster.

Being the good boyscouts, but mainly because of [the comment in the
review](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12378#note_33302115)
the words used for classes and variables are changed to not use builds
anymore.