Added some missing fields to the GlobalTask request body

Author: c8y3

docs/api_reference/reference/v2.1.0/schemas/GlobalTask.yaml

@@ -32,9 +32,9 @@ properties:
       - integer
       - 'null'
   task_close_date:
-    type:
-      - integer
-      - 'null'
+    anyOf:
+      - $ref: ../schemas/iso_date.yaml
+      - type: 'null'
 example:
   task_id: 9
   task_title: Task title

docs/api_reference/reference/v2.1.0/schemas/requestBodies/GlobalTask.yaml

@@ -13,6 +13,18 @@ properties:
     description: A user ID for whom the task will be assigned
   task_tags:
     type: string
+  task_open_date:
+    $ref: ../../schemas/iso_date.yaml
+  task_userid_open:
+    type: integer
+  task_last_update:
+    $ref: ../../schemas/iso_date.yaml
+  task_userid_update:
+    type: integer
+  task_close_date:
+    $ref: ../../schemas/iso_date.yaml
+  task_userid_close:
+    type: integer
 required:
   - task_title
   - task_status_id