settings: Set width of dropdown toggle same as select elements.

This commit sets width of toggle buttons for dropdown list
widget elements same as select elements in both organization
settings. We set the min-width to be 325px and max-width to
100%.

web/styles/settings.css

@@ -359,7 +359,8 @@ td .button {
         color: hsl(0, 0%, 20%);
     }
 
-    .settings_select {
+    .settings_select,
+    .dropdown-list-widget .dropdown-toggle {
         height: 30px;
         min-width: 325px;
         max-width: 100%;