autocomplete: update html data attributes.

* Remove the `source` and `weight` html data attributes (no longer used).
* Make the `type` html data attribute properly indicate the completion
  type. Valid types: `tag`, `tag-alias`, `tag-abbreviation`,
  `tag-autocorrect`, `tag-other-name`.

app/javascript/src/styles/common/autocomplete.scss

@@ -22,7 +22,7 @@
     color: var(--autocomplete-arrow-color);
   }
 
-  a.tag-type-autocorrect .autocomplete-antecedent {
+  li[data-autocomplete-type="tag-autocorrect"] .autocomplete-antecedent {
     text-decoration: dotted underline;
   }
 }