Fix kitchen_sink options flow defaults

[karwosts]

Proposed change

• Kitchen sink options flow sections demo was not correctly restoring the previously saved values (even though it seemed to be attempting to do so). I have fixed this to retrieve the previously saved value.

• Add a select selector for purposes of testing Config Flow: SelectSelectorConfig does not display the saved selected item inside a section frontend#22590, also to exhibit an example usage of selectors and more translations in config flow sections.

• Fix hassfest script which was blocking me from adding a data_description to a section, which I believe should be allowed per https://developers.home-assistant.io/docs/data_entry_flow_index#labels--descriptions

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 Ruff (ruff format 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.

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

[home-assistant]

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

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[gjohansson-ST]

#128965