Improve deprecation message for ec2_vpc_dhcp_options modules (#38459)

Make it clear to user why ec2_vpc_dhcp_options and
ec2_vpc_dhcp_options_facts have been deprecated

lib/ansible/modules/cloud/amazon/ec2_vpc_dhcp_option.py

@@ -286,6 +286,11 @@ def main():
     )
 
     module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
+    if module._name == 'ec2_vpc_dhcp_options':
+        module.deprecate("The 'ec2_vpc_dhcp_options' module has been renamed "
+                         "'ec2_vpc_dhcp_option' (option is no longer plural)",
+                         version=2.8)
+
     params = module.params
     found = False
     changed = False

lib/ansible/modules/cloud/amazon/ec2_vpc_dhcp_option_facts.py

@@ -126,6 +126,10 @@ def main():
 
     module = AnsibleModule(argument_spec=argument_spec,
                            supports_check_mode=True)
+    if module._name == 'ec2_vpc_dhcp_options_facts':
+        module.deprecate("The 'ec2_vpc_dhcp_options_facts' module has been renamed "
+                         "'ec2_vpc_dhcp_option_facts' (option is no longer plural)",
+                         version=2.8)
 
     # Validate Requirements
     if not HAS_BOTO3: