MDL-70829 tool_lp: Remove presentation role for decorative images

* Behat tests in report_competency added to test the user summary
display in the user competency summary modal.

admin/tool/lp/templates/form-user-selector-suggestion.mustache

@@ -49,7 +49,7 @@
     }
 }}
 <span>
-    <img height="12" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="12" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
     {{#hasidentity}}
     <span><small>{{identity}}</small></span>

admin/tool/lp/templates/user_summary.mustache

@@ -50,7 +50,7 @@
 }}
 <span>
     <a href="{{profileurl}}" title="{{#str}}viewprofile{{/str}}">
-    <img height="18" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="18" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
     {{#hasidentity}}
     <span><small>{{identity}}</small></span>

report/competency/tests/behat/breakdown_by_activity.feature

@@ -65,3 +65,10 @@ Feature: See the competencies for an activity
     And I click on "PageName1" "autocomplete_selection"
     And I should see "Test-Comp1"
     And I should see "Test-Comp2"
+
+  @accessibility
+  Scenario: Evaluate the accessibility of the user competency summary dialogue
+    Given I navigate to "Reports" in current page administration
+    When I click on "Competency breakdown" "link"
+    And I click on "Not rated" "link"
+    And the page should meet accessibility standards