Add github_organization_credential_authorization table

[Kanthi-Hegde]

Description

The plugin currently has no way to query classic personal access tokens (PATs) that members have authorized against an organization. This PR adds a new github_organization_credential_authorization table to close that gap.

It wraps GitHub's List SAML SSO authorizations for an organization REST API (GET /orgs/{org}/credential-authorizations), which is the only API GitHub exposes for classic PATs at the org level. The same endpoint also returns authorized SSH keys, distinguishable via the credential_type column.

What's included

• New table: github_organization_credential_authorization
• Registration in plugin.go
• Docs page with usage guide, required permissions, and example queries

Columns

login, credential_id, token_last_eight, scopes, credential_type, credential_authorized_at, credential_accessed_at, authorized_credential_id, authorized_credential_note, authorized_credential_expires_at, authorized_credential_title, fingerprint.

Notes

• The organization qualifier is required.
• This endpoint requires an organization owner token (admin:org) and is only available for organizations on GitHub Enterprise Cloud with SAML SSO enabled; other orgs return no rows. A 403/404 is treated as an empty result, consistent with other org-scoped tables in this plugin.