Block Attributes ID is showing null

Problem/Motivation

If you will add user account menu and main menu on page, it will show duplicate `id` for blocks. Because block attributes ids are showing null. It might be some context issue

Steps to reproduce

Go to page where you have added account menu or main menu. And inspect page. You will find id value something like `{missing_id}-menu`:

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes