MDL-67541 core_grades: Add max and min grade to mustache.

grade/templates/grades/grader/gradingpanel/point.mustache

@@ -29,7 +29,7 @@
 <form>
   <div class="mb-3">
     <label for="core_grades-grade-{{uniqid}}">{{#str}}gradenoun, moodle{{/str}}</label>
-    <input class="form-control" type="number" name="grade" value="{{grade}}" id="core_grades-grade-{{uniqid}}" aria-describedby="core_grades-help-{{uniqid}}">
+    <input class="form-control" type="number" name="grade" value="{{grade}}" id="core_grades-grade-{{uniqid}}" aria-describedby="core_grades-help-{{uniqid}}" min="0" max="{{maxgrade}} " step="any">
     <small id="core_grades-help-{{uniqid}}" class="form-text text-muted">{{#str}}grade_help, core_grades{{/str}}</small>
   </div>
 </form>