Make state exists universal in collection (#13890)

Make state: exists available for all API modules

Make state:exists return the ID just like it would if it created the resource

awx_collection/tests/integration/targets/credential/tasks/main.yml

@@ -47,6 +47,42 @@
     that:
       - "result is changed"
 
+- name: Create an Org-specific credential with an ID with exists
+  credential:
+    name: "{{ ssh_cred_name1 }}"
+    organization: Default
+    credential_type: Machine
+    state: exists
+  register: result
+
+- assert:
+    that:
+      - "result is not changed"
+
+- name: Delete an Org-specific credential with an ID
+  credential:
+    name: "{{ ssh_cred_name1 }}"
+    organization: Default
+    credential_type: Machine
+    state: absent
+  register: result
+
+- assert:
+    that:
+      - "result is changed"
+
+- name: Create an Org-specific credential with an ID with exists
+  credential:
+    name: "{{ ssh_cred_name1 }}"
+    organization: Default
+    credential_type: Machine
+    state: exists
+  register: result
+
+- assert:
+    that:
+      - "result is changed"
+
 - name: Delete a Org-specific credential
   credential:
     name: "{{ ssh_cred_name1 }}"