ACI: Various changes to module documentation and guide (#36516)

* ACI: Various changes to module documentation and guide

This PR includes:
- We moved the object class information to the notes
- Add version information to guide chapters
- Add generic note to modules with reference to ACI guide
- Reference known issues in aci_rest documentation
- Remove module_utils function docs from modules
- Indicate which parameters are not required for querying all objects
- Added missing RETURN information

* Fix copyright strings

* Remove aci_domain_to_encap_pool.py for v2.5

* More updates

* PEP8 fix

* Improve listings of parameters/return values

lib/ansible/modules/network/aci/aci_config_snapshot.py

@@ -18,15 +18,15 @@ description:
 - Manage Config Snapshots on Cisco ACI fabrics.
 - Creating new Snapshots is done using the configExportP class.
 - Removing Snapshots is done using the configSnapshot class.
+notes:
+- The APIC does not provide a mechanism for naming the snapshots.
+- 'Snapshot files use the following naming structure: ce_<config export policy name>-<yyyy>-<mm>-<dd>T<hh>:<mm>:<ss>.<mss>+<hh>:<mm>.'
+- 'Snapshot objects use the following naming structure: run-<yyyy>-<mm>-<dd>T<hh>-<mm>-<ss>.'
 - More information from the internal APIC classes I(config:Snapshot) and I(config:ExportP) at
   U(https://developer.cisco.com/docs/apic-mim-ref/).
 author:
 - Jacob McGill (@jmcgill298)
 version_added: '2.4'
-notes:
-- The APIC does not provide a mechanism for naming the snapshots.
-- 'Snapshot files use the following naming structure: ce_<config export policy name>-<yyyy>-<mm>-<dd>T<hh>:<mm>:<ss>.<mss>+<hh>:<mm>.'
-- 'Snapshot objects use the following naming structure: run-<yyyy>-<mm>-<dd>T<hh>-<mm>-<ss>.'
 options:
   description:
     description:
@@ -215,7 +215,7 @@ def main():
     argument_spec = aci_argument_spec()
     argument_spec.update(
         description=dict(type='str', aliases=['descr']),
-        export_policy=dict(type='str', aliases=['name']),
+        export_policy=dict(type='str', aliases=['name']),  # Not required for querying all objects
         format=dict(type='str', choices=['json', 'xml']),
         include_secure=dict(type='bool'),
         max_count=dict(type='int'),
@@ -261,7 +261,6 @@ def main():
 
         aci.get_existing()
 
-        # Filter out module params with null values
         aci.payload(
             aci_class='configExportP',
             class_config=dict(