Add last changes to Textual create

[mirpedrol]

nf-core#2404

• If the pipeline exists, don't allow to continue and show a "back" button instead.
• Option to set the repo name
• Option to set github org
• If the repo exists, show information about how to push to a repo manually.

⚠️

• To clear the rich log consol doesn't always work
  - When giving a different repo name, a new pipeline is created with this new name, resulting in two local folders.