fix: added reset search method

[OwenCoogan]

What does this PR do?

https://www.loom.com/share/5879bdc463d14439ab3ab2085ca7da6f

This small fix clears stale search input state in the OSS power select when the dropdown is closed.

• resets the search value via the onSearch callback with an empty string
• prevents old query text from being reused when the component is reopened
• keeps the list filtering behavior consistent with the current open/closed state

Related to: #

What are the observable changes?

Good PR checklist

• Title makes sense
• Is against the correct branch
• Only addresses one issue
• Properly assigned
• Added/updated tests
• Added/updated documentation with Figma design link. Don't forget to replace "design" by "file" in the URL. For example https://www.figma.com/file/example
• Migrated touched components to Glimmer Components
• Properly labeled

[linear-code]

DRA-2654

[edouardmisset]

nice job

[OwenCoogan]