This commit redesign the polls and increases characters limit for the
options from 25 to 50 characters, giving pollsters more freedom.
Summarizing, the redesign is making the polls more adaptive for upcoming
changes to the options characters limit: the bar, or a "chart", is now
displayed separately from the option itself; vote check mark is moved
next to the option text, making the percentages take less space. Option
lengths are taken into account and text is wrapped to multiple lines
if necessary to avoid overflow.
* Add voters count to polls
* Add ActivityPub serialization and parsing of voters count
* Add support for voters count in WebUI
* Move incrementation of voters count out of redis lock
* Reword “voters” to “people”
