MDL-67673 phpunit: Fix the return type of template methods

All the setup/teardown/pre/post/conditions template methods
now are required to return void. This was warned with phpunit 7
and now is enforced.

At the same time, fix a few wrong function names,
provider data and param types, return statements...

course/format/weeks/tests/observer_test.php

@@ -36,7 +36,7 @@ class format_weeks_observer_testcase extends advanced_testcase {
     /**
      * Test setup.
      */
-    public function setUp() {
+    public function setUp(): void {
         $this->resetAfterTest();
     }
 

course/tests/category_hooks_test.php

@@ -37,7 +37,7 @@ use PHPUnit\Framework\MockObject\MockObject;
  */
 class core_course_category_hooks_testcase extends \advanced_testcase {
 
-    protected function setUp() {
+    protected function setUp(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
     }

course/tests/category_test.php

@@ -32,7 +32,7 @@ class core_course_category_testcase extends advanced_testcase {
 
     protected $roles;
 
-    protected function setUp() {
+    protected function setUp(): void {
         parent::setUp();
         $this->resetAfterTest();
         $user = $this->getDataGenerator()->create_user();

course/tests/customfield_test.php

@@ -40,7 +40,7 @@ class core_course_customfield_testcase extends advanced_testcase {
     /**
      * Set up
      */
-    protected function setUp() {
+    protected function setUp(): void {
         parent::setUp();
         $this->resetAfterTest();
         $this->setAdminUser();

course/tests/events_test.php

@@ -36,7 +36,7 @@ class core_course_events_testcase extends advanced_testcase {
     /**
      * Tests set up
      */
-    protected function setUp() {
+    protected function setUp(): void {
         global $CFG;
         require_once($CFG->dirroot . '/course/lib.php');
         $this->resetAfterTest();

course/tests/externallib_test.php

@@ -42,7 +42,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
     /**
      * Tests set up
      */
-    protected function setUp() {
+    protected function setUp(): void {
         global $CFG;
         require_once($CFG->dirroot . '/course/externallib.php');
     }

course/tests/search_test.php

@@ -53,7 +53,7 @@ class course_search_testcase extends advanced_testcase {
      */
     protected $customfieldareaid = null;
 
-    public function setUp() {
+    public function setUp(): void {
         $this->resetAfterTest(true);
         set_config('enableglobalsearch', true);