Translation fixes

[balloob]

Breaking change

Proposed change

So I realized that sprinkling the code with __BACKWARDS_COMPAT__ wherever we load translations of states is going to get old really fast and we'll probably miss ones.

So instead I went the other way around: for builds that do not have access to the backend or that will potentially connect to older backends (cast), we merge in a copy of the backend state translations.

Backend translations are created using a new addition to the core repo translations script.

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