review-with-filter includes already reviewed items

https://github.com/GothenburgBitFactory/taskshell/pull/47 fixed #29 (thanks!) in the as-yet-unreleased (?) 1.3.0 stream

However, using `tasksh> review proj:HappyFunBall` shows reviewed, completed, even deleted tasks for review.

Looking at the code, review-with-filter bypasses the `_reviewed` report and its filter entirely (It would be better named `_unreviewed`, but that's besides the point).

So, practically, if I want to review only one project's tasks, I would need to do:

`tasksh> review proj:HappyFunBall and ( reviewed.none: or reviewed.before:now-6days ) and ( +PENDING or +WAITING )`

Ideas of ways forward:

1. Could there be a way to review using an alternate report? Then I could have:

`tasksh> review _reviewed_hfb` where there is `report._reviewed_hfb.filter=proj:HappyFunBall and (reviewed.none: … `

2. Could there be a default concatenation to the filter given? something like this:

```
tasksh.custom_filter_suffix=and ( reviewed.none: or reviewed.before:now-6days ) and ( +PENDING or +WAITING )
```

then `tasksh> review proj:HappyFunBall` would automatically concatenate the `custom_filter_suffix` stuff.