Radio - fix focus ring color and split css

[thrbnhrtmnn]

Description / User Story

With this issue the focus ring color of the radio should be fixed and the css of the whole component should be separated and moved to the right folder.

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Acceptance Criteria

• Separate radio css and move them to their component folders
• Fix color of focus ring in light and dark mode (it is blue but should be black in light and white in dark mode)

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Background information

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