Fix generated Lovelace translating domain names

[balloob]

Breaking change

Proposed change

With the introduction of partial loaded translations, we now don't have access to the translations for domain names when generating Lovelace.

This is a problem because in Lovelace we group entities without an area in cards by their domain and use the translated title as the card title.

The fix is not easy, because when we load translations the updated hass object still has to propagate from the root element to where we are calling the function.

So this PR implements one proposal to fix this: return the updated hass from the hass.loadBackendTranslations function.

I don't like this fix.

Alternative that Bram thought of: allow localizing at the root via an event. That won't work in this case as we pass the localize function to generate Lovelace.

Alternative ideas:

• Allow setting translation keys as card headers, so hass updating the card will update the translation. This can work but adds more logic to ha-card for something that is rarely used.

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:
• 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

[bramkragten]

I think this is a little bit better, I can live with it now...