Complete persistent notifications migration

[bdraco]

frontend: home-assistant/frontend#16476

Breaking change

Persistent notifications are no longer stored in the state machine.

The notification_id is no longer mutated with slugify. When calling the dismiss service, always pass the original notification_id that was passed in.

Proposed change

The migration (started in #57157) to using a websocket subscription for persistent notifications is complete.

This solves the following problems:

• Events being fired (and stored in the database)
• Notifications being stored in the state machine (and stored in the database)
• Having to poll for notifications when the event was fired (now pushed via subscribe)
• Thundering herd problem at startup if lots of devices are discovered
• All notifications being sent every time (larger payload than needed)

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.
• Untested files have been added to .coveragerc.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

TODO:

• tests
• frontend Complete persistent notifications migration frontend#16476
• figure out how to handle configurator -- is this needed?
  looks like it still works

[home-assistant]

Hey there @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (persistent_notification) you are listed as a code owner for? Thanks!

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[balloob]

We should mark the removal from the state machine as a breaking change. Some people have used it in the past to automatically dismiss certain notifications.

[bdraco]

Adjusted the text.
Do we need to give them an alternative way to enumerate them? (poc in #94113)