Bugfix keycloak client do not report changes when there is none (#3610)

* KeycloakClientDiffBugs - Introduce test that passes.

* KeycloakClientDiffBugs - Add test to show that checking of redirect_uri's fails.

* KeycloakClientDiffBugs - (Fix1) Update so that checking of `redirectUris` no longer shows a change.

* KeycloakClientDiffBugs - Add test to show that checking of attributes's fails (sorting issue)

* KeycloakClientDiffBugs - (Fix2) Update so that checking of `attributes` no longer shows a change.

* KeycloakClientDiffBugs - Add test to show that checking of protocol_mappers's fail

* KeycloakClientDiffBugs - (Fix3) Update so that checking of `protocol_mappers` no longer shows a change when there is none.

* Introduce code fragment.

* Update the changelog to be based on the PR instead of the issue.

* Fix the readme

* Fix yaml indentation.

* Fix pep8

* Update changelogs/fragments/3610-fix-keycloak-client-diff-bugs-when-sorting.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update changelogs/fragments/3610-fix-keycloak-client-diff-bugs-when-sorting.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/identity/keycloak/keycloak_client.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Remove need for .copy() after making normalise_cr not mutate the dict.

Co-authored-by: Pierre Dumuid <pierre@knowyourdata.com.au>
Co-authored-by: Felix Fontein <felix@fontein.de>

tests/integration/targets/keycloak_client/docker-compose.yml

@@ -0,0 +1,26 @@
+version: '3.4'
+
+services:
+  postgres:
+    image: postgres:9.6
+    restart: always
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+
+  keycloak:
+    image: jboss/keycloak:12.0.4
+    ports:
+      - 8080:8080
+
+    environment:
+      DB_VENDOR: postgres
+      DB_ADDR: postgres
+      DB_DATABASE: postgres
+      DB_USER: postgres
+      DB_SCHEMA: public
+      DB_PASSWORD: postgres
+
+      KEYCLOAK_USER: admin
+      KEYCLOAK_PASSWORD: password