AUTH-6588 Replace Access app SelfHostedDomains with Destinations

[veggiedefender]

Description

Access team is deprecating the self_hosted_domains field for apps in favor of a new destinations field to give us more flexibility in defining different types of domains. This PR adds the new field and removes the old one. I hate to do a breaking change, but it's pretty much always incorrect to send both fields if you mean to change just one, so I think that the toil is worth avoiding the footgun.

Also adds the domain_type field. Now that they can be either private or public, we needed a way to indicate the type of the "primary" domain.

Has your change been tested?

Tests pass! And I used the library to manually create/read/update apps.

Types of changes

What sort of change does your code introduce/modify?

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• This change is using publicly documented in cloudflare/api-schemas
  and relies on stable APIs.

[github-actions]

changelog detected ✅

[github-actions]

This functionality has been released in v0.111.0.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!