Polls: Construct an html field during normalization.

Input of emoji in polls could use some work, but it's a different issue.

Closes #589 (closed)

src/components/poll/poll.vue

@@ -17,7 +17,7 @@
           <span class="result-percentage">
             {{ percentageForOption(option.votes_count) }}%
           </span>
-          <span>{{ option.title }}</span>
+          <span v-html="option.title_html"></span>
         </div>
         <div
           class="result-fill"