Commit detail has unclickable button with notes count

Description

As seen in this example commit detail, there's an unclickable button in the header with the number of notes for that commit (mentions, comments, etc.). Not sure why we have that count there, with a comment icon.

This is the code that generates it:

- if defined?(@notes_count) && @notes_count > 0
      %span.btn.disabled.btn-grouped.hidden-xs.append-right-10
        = icon('comment')
        = @notes_count

It’s not even a button, it’s a span 🤔

Proposal

Currently, the notes (mentions, comments, etc.) for a commit are being shown below the changes in the “Changes” tab. Maybe these should be moved from the “Changes” tab to a new “Activity” tab (that would have the count of notes).

Remove the count of notes on the commit.