Fixes a few minor issues with the multiselect dropdown

1. Label no longer bleeds into the downward arrow icon
2. The selection number no longer breaks onto its own line
3. Options have a min-width so short labels can't result in small click
   targets

ui/app/styles/components/dropdown.scss

@@ -73,6 +73,8 @@
 .dropdown-trigger-label {
   margin-left: 8px;
   margin-right: 8px;
+  display: inline-block;
+  white-space: nowrap;
 }
 
 .ember-power-select-selected-item,
@@ -125,6 +127,7 @@
     label {
       display: block;
       padding: 3px 8px;
+      min-width: 100px;
       cursor: pointer;
     }
 
@@ -139,6 +142,7 @@
       border-left: 2px solid $blue;
       label {
         padding-left: 6px;
+        min-width: 98px;
       }
     }
   }