MDL-71817 calendar: change the calendar heading to h4 in the block

This commit adds the logic that change the size of the calendar
header depending if the user is viewing in the block or in the
full view.

calendar/lib.php

@@ -3501,6 +3501,7 @@ function calendar_get_view(\calendar_information $calendar, $view, $includenavig
         $data = $month->export($renderer);
         $data->viewingmonth = true;
         $data->showviewselector = ($view == "month");
+        $data->viewinginblock = ($view == "monthblock");
     } else if ($view == "day") {
         $day = new \core_calendar\external\calendar_day_exporter($calendar, $related);
         $data = $day->export($renderer);

calendar/templates/month_navigation.mustache

@@ -46,7 +46,12 @@
             <span class="arrow_text">{{previousperiodname}}</span>
         </a>
         <span class="hide"> | </span>
-        <h2 class="current">{{periodname}}</h2>
+        {{#viewinginblock}}
+            <h4 class="current">{{periodname}}</h4>
+        {{/viewinginblock}}
+        {{^viewinginblock}}
+            <h2 class="current">{{periodname}}</h2>
+        {{/viewinginblock}}
         <span class="hide"> | </span>
         <a{{!
             }} href="{{nextperiodlink}}"{{!