feat: hide empty groups in search results

[jack66128]

Feature description

When using the search bar to filter services, hide groups where none of their services match the search terms.

Motivation

This would make for cleaner search results, particularly if there are many groups. Services can be hidden under the keyboard, requiring the user to dismiss the keyboard to check if the search actually returned anything.

Acknowledgements

• This issue is not a duplicate of an existing feature request.
• I have chosen an appropriate title.
• All requested information has been provided properly.