Move API Reference (#23777)

* merge mattermost-api-reference unchanged

* api: update repostiory paths

* api: drop GitPod for api (for now)

* api: improved node_modules target

* api: relocate GitHub actions to root

* Update .github/workflows/api.yml

Co-authored-by: Antonis Stamatiou <stamatiou.antonis@gmail.com>

* fix cache-dependency-path

* adopt node-version-file

* pin versions for uses

* tidy steps/runs

* api/.gitpod.yml: tidy

* api: rm now unused .gitlab-ci.yml

---------

Co-authored-by: Antonis Stamatiou <stamatiou.antonis@gmail.com>

api/v4/source/permissions.yaml

@@ -0,0 +1,32 @@
+  /api/v4/permissions/ancillary:
+    get:
+      tags:
+        - permissions
+      summary: Return all system console subsection ancillary permissions
+      description: >
+        Returns all the ancillary permissions for the corresponding system console
+        subsection permissions appended to the requested permission subsections.
+
+
+        __Minimum server version__: 5.35
+      operationId: GetAncillaryPermissions
+      parameters:
+        - name: subsection_permissions
+          in: query
+          description: >
+            The subsection permissions to return the ancillary permissions for.
+            These values are comma seperated.
+            Ex. subsection_permissions=sysconsole_read_reporting_site_statistics,sysconsole_write_reporting_site_statistics,sysconsole_write_user_management_channels
+          schema:
+            type: string
+      responses:
+        "200":
+          description: Successfully returned all ancillary and requested permissions
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  type: string
+        "400":
+          $ref: '#/components/responses/BadRequest'