Add missing localizations for Voice Assistants > Expose headers

[NoRi2909]

Proposed change

The Icon and the Remove columns of the Expose tab for Settings > Voice Assistants are lacking localizable labels so they show up with their lowercase variable names only:

This PR adds two string definitions to en.json and the necessary code to ha-config-voice-assistants-expose.ts

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

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

[NoRi2909]

@silamon Edit: Now I figured it out …

As long as everything fits in 80 chars it wants everything on a single line, with one character more it has to be split into several lines. Learning something new every day …