MDL-73476 phpunit: events, external and search tescase names

All events_test, external_test and search_test classes:

- Namespaced with component[\level2-API]
- Moved to level2-API subdirectory when required.
- Fixed incorrect use statements with leading backslash.
- Changed code to point to global scope when needed.
- Fix some relative paths and comments here and there.
- All them passing individually.
- Complete runs passing too.

Special mention to lib/external/tests/external_test.php:
- external is not a valid component
- hence, its only valid namespace is "core"
- also, it's testing lib/external/externallib.php
- hence, the file (and class) have been renamed to external_externallib_test.php
  (to avoid conflicts with other external_test that may exist in core)

admin/tool/analytics/tests/external_test.php → admin/tool/analytics/tests/external/external_test.php

@@ -24,13 +24,17 @@
  * @since      Moodle 3.8
  */
 
+namespace tool_analytics\external;
+
+use externallib_advanced_testcase;
+
 defined('MOODLE_INTERNAL') || die();
 
 global $CFG;
 
 require_once($CFG->dirroot . '/webservice/tests/helpers.php');
-require_once(__DIR__ . '/../../../../analytics/tests/fixtures/test_indicator_max.php');
-require_once(__DIR__ . '/../../../../analytics/tests/fixtures/test_target_course_level_shortname.php');
+require_once($CFG->dirroot . '/analytics/tests/fixtures/test_indicator_max.php');
+require_once($CFG->dirroot . '/analytics/tests/fixtures/test_target_course_level_shortname.php');
 
 /**
  * Tool analytics external functions tests
@@ -41,7 +45,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since      Moodle 3.8
  */
-class tool_analytics_external_testcase extends externallib_advanced_testcase {
+class external_test extends externallib_advanced_testcase {
 
     /**
      * test_potential_contexts description
@@ -73,7 +77,7 @@ public function test_potential_contexts_no_manager() {
         $user = $this->getDataGenerator()->create_user();
         $this->setUser($user);
 
-        $this->expectException(required_capability_exception::class);
+        $this->expectException(\required_capability_exception::class);
         $this->assertCount(2, \tool_analytics\external::potential_contexts());
     }
 }

admin/tool/capability/tests/events_test.php → admin/tool/capability/tests/event/events_test.php

@@ -22,7 +22,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later.
  */
 
-defined('MOODLE_INTERNAL') || die();
+namespace tool_capability\event;
 
 /**
  * Class for capability overview events.
@@ -31,7 +31,7 @@
  * @copyright  2014 Petr Skoda
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later.
  */
-class tool_capability_events_testcase extends advanced_testcase {
+class events_test extends \advanced_testcase {
 
     /**
      * Setup testcase.
@@ -54,11 +54,11 @@ public function test_report_viewed() {
         $event = reset($events);
 
         $this->assertInstanceOf('\tool_capability\event\report_viewed', $event);
-        $this->assertEquals(context_system::instance(), $event->get_context());
+        $this->assertEquals(\context_system::instance(), $event->get_context());
         $expected = array(SITEID, "admin", "tool capability", "tool/capability/index.php");
         $this->assertEventLegacyLogData($expected, $event);
         $this->assertEventContextNotUsed($event);
-        $url = new moodle_url('/admin/tool/capability/index.php');
+        $url = new \moodle_url('/admin/tool/capability/index.php');
         $this->assertEquals($url, $event->get_url());
         $event->get_name();
     }