housekeep: TU rename - code changes

Renaming of symbols. Functions, variables, values, DB values, etc.
Basically everything that is not user-facing.

This only covers "Trusted User" things:
tests, comments, etc. will covered in a following commit.

templates/partials/packages/search_actions.html

@@ -4,7 +4,7 @@
             <option value="unflag">{{ "Unflag Out-of-date" | tr }}</option>
             <option value="adopt">{{ "Adopt Packages" | tr }}</option>
             <option value="disown">{{ "Disown Packages" | tr }}</option>
-        {% if request.user.is_trusted_user() or request.user.is_developer() %}
+        {% if request.user.is_package_maintainer() or request.user.is_developer() %}
             <option value="delete">{{ "Delete Packages" | tr }}</option>
         {% endif %}
         <option value="notify">{{ "Notify" | tr }}</option>

templates/partials/packages/statistics.html

@@ -44,7 +44,7 @@
             <td class="stat-desc">
                 {{ "Trusted Users" | tr }}
             </td>
-            <td>{{ trusted_user_count }}</td>
+            <td>{{ package_maintainer_count }}</td>
         </tr>
     </table>
 </div>

templates/tu/index.html

@@ -7,11 +7,11 @@
             <tbody>
                 <tr>
                     <td>{{ "Total" | tr }} {{ "Trusted Users" | tr }}:</td>
-                    <td>{{ trusted_user_count }}</td>
+                    <td>{{ package_maintainer_count }}</td>
                 </tr>
                 <tr>
                     <td>{{ "Active" | tr }} {{ "Trusted Users" | tr }}:</td>
-                    <td>{{ active_trusted_user_count }}</td>
+                    <td>{{ active_package_maintainer_count }}</td>
                 </tr>
             </tbody>
         </table>