aci_rest: Fix error handling and improve documentation (#36295)

This PR includes:
- A fix for a recently introduced issue wrt. error handling
- Added integration tests for provoked errors
- Influence standard return values using aci library for aci_rest
- Add proxy support documentation
- Documentation update related to #34175

test/integration/targets/aci_rest/tasks/json_inline.yml

@@ -1,12 +1,8 @@
 # Test code for the ACI modules
-# Copyright 2017, Dag Wieers <dag@wieers.com>
+# Copyright: (c) 2017, Dag Wieers (@dagwieers) <dag@wieers.com>
 
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 
-- name: Test that we have an ACI APIC host, ACI username and ACI password
-  fail:
-    msg: 'Please define the following variables: aci_hostname, aci_username and aci_password.'
-  when: aci_hostname is not defined or aci_username is not defined or aci_password is not defined
 
 # CLEAN ENVIRONMENT
 - name: Remove tenant
@@ -19,7 +15,6 @@
     use_proxy: '{{ aci_use_proxy | default(true) }}'
     path: /api/mo/uni/tn-[ansible_test].json
     method: delete
-  delegate_to: localhost
 
 # ADD TENANT
 - name: Add tenant (normal mode)