MDL-68678 user: Made filterset match text clearer

Part of MDL-67743

lang/en/user.php

@@ -30,7 +30,9 @@ $string['applyfilters'] = 'Apply filters';
 $string['clearfilterrow'] = 'Remove filter row';
 $string['clearfilters'] = 'Clear filters';
 $string['countparticipantsfound'] = '{$a} participants found';
+$string['filtersetmatchdescription'] = 'How multiple filters should be combined';
 $string['match'] = 'Match';
+$string['matchofthefollowing'] = 'of the following:';
 $string['placeholdertypeorselect'] = 'Type or select...';
 $string['placeholdertype'] = 'Type...';
 $string['privacy:courserequestpath'] = 'Requested courses';

user/templates/participantsfilter.mustache

@@ -42,12 +42,16 @@
 
 <div id="core_user-participantsfilter-{{uniqid}}" class="filter-group my-2 p-2 bg-light border-radius border" data-table-region="{{tableregionid}}" data-table-course-id="{{courseid}}" data-filterverb="1">
     <div data-filterregion="filtermatch" class="hidden">
-        <label for="core_user-local-participantsfilter-jointype-{{uniqid}}" class="my-0">{{#str}}match, core_user{{/str}}</label>
-        <select class="custom-select" data-filterfield="join" id="core_user-local-participantsfilter-jointype-{{uniqid}}">
+        <label for="core_user-local-participantsfilter-jointype-{{uniqid}}" class="my-0" aria-hidden="true">
+            {{#str}}match, core_user{{/str}}
+        </label>
+        <select class="custom-select" data-filterfield="join" id="core_user-local-participantsfilter-jointype-{{uniqid}}"
+                aria-label="{{#str}}filtersetmatchdescription, core_user{{/str}}">
             <option value="0">{{#str}}none{{/str}}</option>
             <option selected=selected value="1">{{#str}}any{{/str}}</option>
             <option value="2">{{#str}}all{{/str}}</option>
         </select>
+        <span aria-hidden="true">{{#str}}matchofthefollowing, core_user{{/str}}</span>
     </div>
 
     <div data-filterregion="filters">