This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
* Extract validation logic into a service object.
* Extract logic for updating polls custom fields into a service object.
* Use `strip_heredoc` instead.
* FIX: Polls do not update when configuration has been changed.
Sam Saffron
Bianca Nenciu
Régis Hanol
Guo Xiang Tan