Add all participation states to the filter.
Add all participation states to the filter.

See comment
https://github.com/liqd/a4-meinberlin/pull/1067#pullrequestreview-79233671

liqd/a4-meinberlin,liqd/a4-meinberlin,liqd/a4-meinberlin,liqd/a4-meinberlin