Revert font awesome 5 changes

We are still pushing ahead on this 100% just need a bit longer to prepare
all plugins

plugins/poll/assets/javascripts/discourse/templates/modal/poll-ui-builder.hbs

@@ -73,5 +73,5 @@
 {{/d-modal-body}}
 
 <div class="modal-footer">
-  {{d-button action="insertPoll" icon="chart-bar" class='btn-primary' label='poll.ui_builder.insert' disabled=disableInsert}}
+  {{d-button action="insertPoll" icon="bar-chart-o" class='btn-primary' label='poll.ui_builder.insert' disabled=disableInsert}}
 </div>

plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6

@@ -32,7 +32,7 @@ function initializePollUIBuilder(api) {
   api.addToolbarPopupMenuOptionsCallback(function() {
     return {
       action: "showPollBuilder",
-      icon: "chart-bar",
+      icon: "bar-chart-o",
       label: "poll.ui_builder.title",
       condition: "canBuildPoll"
     };

plugins/poll/assets/javascripts/widgets/discourse-poll.js.es6

@@ -39,9 +39,9 @@ createWidget("discourse-poll-option", {
     const chosen = vote.indexOf(option.id) !== -1;
 
     if (attrs.isMultiple) {
-      result.push(iconNode(chosen ? "far-check-square" : "far-square"));
+      result.push(iconNode(chosen ? "check-square-o" : "square-o"));
     } else {
-      result.push(iconNode(chosen ? "far-dot-circle" : "far-circle"));
+      result.push(iconNode(chosen ? "dot-circle-o" : "circle-o"));
     }
     result.push(" ");
     result.push(optionHtml(option));