feat: add language to community

[Anyitechs]

This PR allow's the community admin to set the preferred language for the published messages in their channel.

Resolves #304

Summary by CodeRabbit

• New Features

  • Communities can set a preferred language; admin UI and a wizard/command let admins configure it.
  • Published buy/sell messages and order descriptions use the community's configured language when set.

• Localization

  • Added language management UI and prompts across 10 supported languages (en, es, fr, de, it, pt, ru, uk, ko, fa).
  • Validation and feedback added for invalid language codes.

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