MDL-65078 competencies: fix webservice

The webservice list_course_module_competencies calls a function that does not exist.

Thanks to Marie-Eve Lévesque for reporting this issue.

competency/classes/api.php

@@ -1205,7 +1205,7 @@ class api {
         $result = array();
 
         // TODO We could improve the performance of this into one single query.
-        $coursemodulecompetencies = course_competency::list_course_module_competencies($cm->id);
+        $coursemodulecompetencies = course_module_competency::list_course_module_competencies($cm->id);
         $competencies = course_module_competency::list_competencies($cm->id);
 
         // Build the return values.

competency/tests/api_test.php

@@ -2757,6 +2757,16 @@ class core_competency_api_testcase extends advanced_testcase {
         $result = api::list_course_module_competencies_in_course_module($cm->id);
         $this->assertEquals($result[0]->get('competencyid'), $c->get('id'));
         $this->assertEquals($result[1]->get('competencyid'), $c2->get('id'));
+
+        // Now get the course competency and coursemodule competency together.
+        $result = api::list_course_module_competencies($cm->id);
+        // Now we should have an array and each element of the array should have a competency and
+        // a coursemodulecompetency.
+        foreach ($result as $instance) {
+            $cmc = $instance['coursemodulecompetency'];
+            $c = $instance['competency'];
+            $this->assertEquals($cmc->get('competencyid'), $c->get('id'));
+        }
     }
 
     /**