feat: auth0_managed curated blocklist support

[KartikJha]

🔧 Changes

Adds support for Auth0-curated blocklists to the auth0_network_acl resource and data source via a new auth0_managed attribute on rule match and not_match blocks. This lets a rule match against Auth0-maintained lists (for example auth0.icloud_relay_proxy or auth0.low_reputation) without the practitioner enumerating IPs or ASNs.

This is an Early Access feature: it requires the advanced-breached-password-detection entitlement and the tenant_acl_curated_blocklists feature flag to be enabled on the tenant.

• Schema (resource.go): new auth0_managed TypeList of strings on the rule match schema, with a ValidateDiagFunc requiring the auth0.<name> identifier form (e.g. auth0.icloud_relay_proxy).
• Expand (expand.go): reads auth0_managed into NetworkACLRuleMatch.Auth0Managed, plus a new validateAuth0ManagedMutualExclusivity check that errors if auth0_managed is set on both match and not_match in the same rule, mirroring the API invariant.
• Flatten (flatten.go): surfaces auth0_managed back into state on read.
• Error enrichment (resource.go): create/update wrap 403 responses with a hint naming both required gates (entitlement + feature flag), but only when the rule actually uses auth0_managed.
• Dependency: bumps github.com/auth0/go-auth0 to a pre-release build exposing the Auth0Managed field on NetworkACLRuleMatch.
• Docs & examples: documents the new attribute and adds two example resources (a match blocklist and a not_match allow-unless case demonstrating the mutual-exclusivity boundary).

📚 References

go-auth0-v1 PR

🔬 Testing

• New acceptance tests: TestAccNetworkACLAuth0Managed, TestAccNetworkACLAuth0ManagedValidation (resource) and TestAccNetworkACLDataSourceAuth0Managed (data source), with recorded HTTP fixtures under test/data/recordings/.
• The validation test exercises the mutual-exclusivity error path (auth0_managed set on both match and not_match).
• Run with: make test-acc TESTARGS="-run TestAccNetworkACLAuth0Managed".

📝 Checklist

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)