misc(stripe): Handle Stripe::AuthenticationError when registering stripe webhook URL

[vincent-pochet]

Context

Some PaymentProviders::Stripe::RegisterWebhookJob are failing with a Stripe::AuthenticationError error.
The error message is:

This API call cannot be made with a publishable API key. Please use a secret API key. You can find a list of your API keys at https://dashboard.stripe.com/account/apikeys.

Since this error cannot be handled by Lago, but must be addressed by the Lago organization admin, we need to inform the admin about it by sending a webhook and silent the error.

Description

The PR refactors the stripe webhook endpoint creation by:

• Moving the registration logic from the generic PaymentProviders::StripeService into a dedicated PaymentProviders::Stripe::RegisterWebhookService
• Handling Stripe::AuthenticationError
  • Delivering a payment_provider.error
  • Returning an empty result

[julienbourdeau]

Love the refactor to a dedicated service and moving the list to the model 🫶