Improve search public API implementation

### Description

We should move a way from the use of global functions for this API implementation and do a search library such `@nextcloud/search` 


### Todo

- [x] `nextcloud/search` repo/project
- [ ] Resolve confusion with naming `callback` see : https://github.com/nextcloud/server/pull/43963#discussion_r1513578002
- [ ] https://github.com/nextcloud/documentation/issues/11544
