Replace object type dropdown with free-text input

[ianmuchyri]

Summary

• Removes the fixed RESOURCE_TYPES and ENTITY_TYPES dropdown in the permission block creation form
• Replaces it with a plain text input so users can type any resource type (e.g. resource:invoice)
• Cleans up the now-unused objectTypeOptions helper and related constants

Test plan

• Create a permission block with scope mode object_type or object, select resource as object kind, and type a custom type like resource:invoice
• Verify the typed value is submitted correctly and appears in the review step
• Verify the same flow works for entity kind