Allow rendering helper text from strings.json

[balloob]

Breaking change

Proposed change

Allow specifying helpers for data entry flow dialogs (config flow, options flow). HA-Form already supported this but not all selectors/form components do. This PR updates a couple to get the POC working with the derivative integration.

Material has built-in support for helper text but it's not very friendly for long text. The helper text will always take up the rendered space but only show the helper when it has focus.

See video:

CleanShot.2022-03-23.at.22.49.20.mp4

Backend: home-assistant/core#68604

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:
• 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

[zsarnett]

I think we should make the helper text persistent but can be for another PR