feat: ✨ make sd-accordion searchable

[mariohamann]

Description

shoelace-style/shoelace#1470

Shoelace updated its details component to use details and summary HTML elements. This makes it possible that the content of accordions is searchable and that the accordion opens itself when content is found.

this could be a nice improvement of our component.

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