Extend hidden_fields to allow more complicated field definitions (#872)

SUMMARY
This allows us to ignore e.g. the last-applied-configuration annotation by specifying
metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]
ISSUE TYPE

Feature Pull Request

COMPONENT NAME
hidden_fields
This replaces #643 as I no longer have permissions to push to branches in this repo

Reviewed-by: Bikouo Aubin
Reviewed-by: Helen Bailey <hebailey@redhat.com>
Reviewed-by: GomathiselviS <gomathiselvi@gmail.com>
Reviewed-by: Alina Buzachis

tests/integration/targets/k8s_hide_fields/tasks/main.yml

@@ -77,6 +77,7 @@
         definition: "{{ hide_fields_base_configmap | combine({'data':{'anew':'value'}}) }}"
         hidden_fields:
           - data
+          - metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]
         apply: true
       register: hf6
       diff: true
@@ -86,6 +87,22 @@
         that:
           - hf6.changed
 
+    - name: Ensure hidden fields are not present
+      assert:
+        that:
+          - >-
+            'annotations' not in hf6.result.metadata or
+            'kubectl.kubernetes.io/last-applied-configuration'
+            not in hf6.result.metadata.annotations
+          - >-
+            'annotations' not in hf6.diff.before.metadata or
+            'kubectl.kubernetes.io/last-applied-configuration'
+            not in hf6.diff.before.metadata.annotations
+          - >-
+            'annotations' not in hf6.diff.after.metadata or
+            'kubectl.kubernetes.io/last-applied-configuration'
+            not in hf6.diff.after.metadata.annotations
+
     - name: Hidden field should not show up in deletion
       k8s:
         definition: "{{ hide_fields_base_configmap}}"