fix: 🤔 sd-radio-button does not accept "md" size for radio-button

[Vahid1919]

Current behavior

You cannot set sd-radio-group as size ="md" (options are 'lg', 'sm'). This means that even though sd-radio-button has a "md" size, there is no way to set this since sd-radio-button does not accept "md" as a size option and will reset all sizes set on the child sd-radio-buttons to the default "lg"

Expected behavior

You can set the sd-radio-group's size as "md", in order to showcase medium sizes sd-radio-buttons

Steps to reproduce

Take a look at the Docs page of sd-radio-group and sd-radio-button, the group lacks a size "md" making sd-radio-buttons for this size incompatible.

Technical Information

DoR

• [x] Item has business value
• [ ] Item has been estimated by the team
• [ ] Item is clear and well-defined
• [x] Item dependencies have been identified

DoD

• [ ] Documentation has been created/updated (if applicable)
• [ ] Migration Guide has been created/updated (if applicable)
• [ ] Relevant E2E tests (Features, A11y, Bug fixes) are created/updated
• [ ] Relevant stories (Features, A11y) are created/updated
• [ ] Implementation works successfully on feature branch

[yoezlem]

@coraliefeil why do we only have sm and lg in the group? it would be much easier in code to add a md in the group, otherwise we need some different logic for sd-radio-button with sd-radio-group.