MDL-69166 core: define payment as a subsystem and pg as a plugin type

lib/classes/plugin_manager.php

@@ -1923,6 +1923,9 @@ class core_plugin_manager {
                 'quiz', 'resource', 'scorm', 'survey', 'url', 'wiki', 'workshop'
             ),
 
+            'pg' => [
+            ],
+
             'plagiarism' => array(
             ),
 

lib/components.json

@@ -38,7 +38,8 @@
         "contenttype": "contentbank\/contenttype",
         "theme": "theme",
         "local": "local",
-        "h5plib": "h5p\/h5plib"
+        "h5plib": "h5p\/h5plib",
+        "pg": "payment\/gateway"
     },
     "subsystems": {
         "access": null,
@@ -94,6 +95,7 @@
         "my": "my",
         "notes": "notes",
         "pagetype": null,
+        "payment" : "payment",
         "pix": null,
         "plagiarism": "plagiarism",
         "plugin": null,

lib/tests/component_test.php

@@ -36,7 +36,7 @@ class core_component_testcase extends advanced_testcase {
      * this is defined here to annoy devs that try to add more without any thinking,
      * always verify that it does not collide with any existing add-on modules and subplugins!!!
      */
-    const SUBSYSTEMCOUNT = 71;
+    const SUBSYSTEMCOUNT = 72;
 
     public function setUp(): void {
         $psr0namespaces = new ReflectionProperty('core_component', 'psr0namespaces');