Entity type not specified on forms_steps entry deletion

Problem/Motivation

When using forms_steps on multiple entity type, not only node. The deletion of an entity will delete any steps for any entity having the same id regardless the entity type.

Steps to reproduce

- Create several form steps on different entity type (not only nodes)
- Create entities using form steps (for exemple custom_entity:1 and another_custom_entity:1)
- Delete one of the entities created, these will delete any form step on entity with the same ID

Proposed resolution

Add entity_type_id on entity predelete hook

Remaining tasks

User interface changes

API changes

Data model changes