add Iterative Reviewer for First2Finish and Task type challenges

[kodar007]

No description provided.

[maxceem]

Thanks, @kodar007. I've noticed a couple small issues:

1. After page reloading the selected reviwer is not shown in the field anymore:

   

2. If I select the same reviewer again and click Save I would get error:

   

Note, that we don't have such issues for the challenge type Challenge which uses role Reviewer.

[kodar007]

@maxceem done, could you please adjust prize to incorporate fix for point 1 above?

[maxceem]

@kodar007 prize update to cover the requirement to show the selected reviewer.

Though at the moment it doesn't work for me.

If I create a new task, set internal reviewer, choose user and click Save, I would get an error:

And after reloading the user would not be shown as selected.

[kodar007]

@maxceem just now noticed, working on it

[maxceem]

Thanks, @kodar007. Works good now.