roll up of fixes for eos modules (#21406)

* fixes issue with load_provider() not checking for an existing key
* adds updates to eos_config results key
* lots of minor syntax fixes in eos shared module
* adds eos_argument_spec to eos_eapi

fixes #21402

lib/ansible/modules/network/eos/eos_config.py

@@ -250,6 +250,7 @@ def run(module, result):
                 commands.extend(module.params['after'])
 
         result['commands'] = commands
+        result['updates'] = commands
 
         replace = module.params['replace'] == 'config'
         commit = not module.check_mode