fix: 🤔 sd-input help-text margin top needs to be updated

[MartaPintoTeixeira]

Current behavior

no margin between help-text and input

Expected behavior

figma: change it to margin-top 4
code: use the same margin you use for "error messages"

For the invalid sample instead of "Error message" change copy to "Error text" if applies.

Steps to reproduce

Technical Information

DoR

• Item has business value
• Item has been estimated by the team
• Item is clear and well-defined
• 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