Active review page does not separate reviews I have completed (voted approve / reject on) and those that are in progress (I have commented/needs-info/am tasked with a review)

[Jamu Kakar]

I like the way the active reviews page separates merge propsals into
groups, such as 'Approved reviews ready to land', 'Requested reviews I
can do', etc. They work very well, but I find I often get a bit
confused by 'Reviews I am doing'.

In some of the projects I work on we have a two review policy. If I'm
the first reviewer and I mark a merge proposal as 'Approve' it stays
in this section. Sometimes a branch will sit in that section for a
number of days and I'll forget whether or not I've reviewed it... so
I'll look again only to find out I've already reviewed it.

It would be nice to break it out into two sections:

Reviews I am doing - Merge proposals I've clicked 'Claim review' on
    that are non-'Merged' or non-'Approved' and for which I have not
    left an 'Approve' comment.

Review I have done - Merge proposals I've clicked 'Claim review' on
    that are non-'Merged' or non-'Approved' and for I have left an
    'Approve' comment.