Fix device actions in step-flow-form

[karwosts]

Proposed change

The action selector has some issues when used in a dialog (like a config flow), as device actions implictly rely on consuming the fullEntitiesContext provided by ha-panel-config.

When in a step flow dialog, the dialog is not under the DOM of that ha-panel-config, so the expected entity registry is undefined, leading to significant problems with device actions/conditions/triggers. The frontend just throws exceptions and gets bugged out if you try to use them.

To workaround this, in the action selector I check if the expected entityRegistry is not provided, and create a new producer for it in the action selector if missing, so that the child elements that expect it to exist can function.

Sadly, after making these fixes, using device actions in config flows still does not actually work 😅 . The frontend parts seem to work, but anytime you save and actually trigger the device actions via this method (like with a Template Button), core throws backend errors and says it can't understand the entity_id. But I think that's likely a core bug; so we can fix this first, and then move the investigation there. (Assuming we want device actions to work here).

This could also be an issue if any config flows use Trigger selectors or Condition selectors, though I'm not aware of any that do, so far I've only seen Action selectors used on templates, so I am limiting the fix to that.

Type of change

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

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
  https://community.home-assistant.io/t/error-in-describing-condition-e-is-not-iterable/832113/9
  template switch helper "e is not iterable" on "actions to turn on" or "..off" core#139631
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• 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

[karwosts]

An unrelated bug that causes the config flow form to close every time you select a device action in the action selector.

[bramkragten]

I think we should add lazy loaded context provides, so that the context provider can be on the home-assistant level and dialogs can also use it.

I'll look in to that