Handle errors from updating billing contacts

Design

• Lean on the documentation in PJs around alerts and alert placement
• 🎨 Successful changes Figma

Problem

We need to handle potential backend and graphQL failures that arise when updating billing contacts.

Proposal

• Add entries to the error_dictionary.js for:
  • BillingAccountContact validations
    • Example implementation MR: https://gitlab.com/gitlab-org/customers-gitlab-com/-/merge_requests/8477
  • Zuora contact ID not found
  • SyncBillingAccountContactToZuoraService
    • Update existing errors.add call to use errorType with message
      • Currently using a String for the errorType. Add in a true errorType and also retain the existing message
  • UpdateBillingAccountContactsService call from UpdateContacts mutation
    • Update ZuoraAccountUpdateError/ZuoraContactCreateError to automatically add an error map entry
      • Set up similar to GraphQL where we always errors.add() when the errors are raised
        • Either rescue errors and rethrow after adding to error map, OR find all spots where we're raising and errors.add() before raising (less ideal)

ZuoraAccountUpdateError as StandardError	Backend error message: Unable to update billing account Suggested title: Could not update billing account information Suggested message: An error occurred while updating your billing account. If the problem persists, [contact support](https://about.gitlab.com/support/).
ZuoraContactCreateError as StandardError	Backend error message: Unable to create contact Suggested title: Could not create billing account contact Suggested message: An error occurred while creating your billing account contact. If the problem persists, [contact support](https://about.gitlab.com/support/).
Other Billing account update failure (non-StandardError)	UNEXPECTED_ERROR_MESSAGE