[config:export:single] and chain discovery. Improve command

[igasi]

Problem/Motivation
This command is very powerful, in my case I use it for automate generate configurations for my module relate to ui like views, content, entities, roles, permissions and so on.
For this I created a chain yml file in my module into chains folder. But I think this part can be add in the command as optional ask.

Problem/Motivation
This command is very powerful, in my case I use it for automate generate configurations for my module related to ui like views, content, entities, roles, permissions and so on.
For this I created a chain yml file, into chains folder in my module. This is for update the default config for my module.
I think this part can be add in the command as optional question in the command flow.

Propose solution
After filled current options of the commands. Add new main optional question, for ask if would be include in some module, and other for sub-ask if would be a generate chain file into own module.

# drupal config:export:single
 Configuration type [Simple configuration]:
 > system.simple
 Configuration name [automated_cron.settings]:
 > 
Export configuration into module (yes/no) [no]:
> yes
Enter the module name [webprofiler]:
 > mymodule
Include config as (install/schema/optional) [optional]:
 > optional
Generate a chain yml file (yes/no) [yes]
> yes
Name chain yml file [defaultChain]
>
 Configuration was exported at file 
- modules/custom/mymodule/optional/automated_cron.settings.yml.
- modules/custom/mymodule/console/chain/defaultChain.yml

[jmolivas]

@igasi: we already support a global --generate-chain we may:

1. Add a new option --chain-file
2. If --generate-chain option is detected and add a new ask question

Chain file name, without YML extension [ ]
> 

• If chain file value is empty, just output the value as currently.
• Create file if does not exist, append value in other case.

[igasi]

Then, we can split into 2 this issue:

• [generate:export:single] improve with module assignation and config type (this).
• Second, The new option could be --generate-chain-file, more explicit.
  • Option more explicit.
  • The new general option add the new ask (Name chain file).
  • Create file if does not exist, append value in other case.

# drupal config:export:single --generate-chain-file
 Configuration type [Simple configuration]:
 > system.simple
 Configuration name [automated_cron.settings]:
 > 
Export configuration into module (yes/no) [no]:
> yes
Enter the module name [webprofiler]:
 > mymodule
Include config as (install/schema/optional) [optional]:
 > optional
Name chain file [defaultChain]
> 

 Configuration was exported at file 
- modules/custom/mymodule/optional/automated_cron.settings.yml.
- modules/custom/mymodule/console/chain/defaultChain.yml