Since 92f5cfd8 we support "mw-notalk" to suppressing comment detection
in pages or sections.
Until now, it only worked when the comment timestamp was surrounded by
a marked element. However, when a marked element was directly adjacent
to a comment, it would sometimes become a part of the comment range.
This can no longer happen now.
Existing use cases for this were the {{outdent}} and {{tracked}}
templates, which we handle specially since 50ad5bb2 and ddd391b6.
It's a bit ugly to hardcode specific templates like that, and this
provides a better solution for the future. The added test case
displays some other potential uses.
Bug: T324132
Change-Id: I7ffd299ef5957b35da8d01f9a0ed5a7a9a78be83
