This is a plain value object that represents the action being filtered,
replacing associative arrays that were being used up to this point.
We should now check whether it's possible to make it not require an
accountname (which complicates things), and then use it in related
classes as well, e.g. Parameters.
Change-Id: I9550c14819b600c97c46b632cc1c2d447972d69c
