Refactored the MultiSelectWithSearch function and related interfaces to use a MultiSelectSearchResult struct instead of multiple return values. This change improves clarity and extensibility of the search function signature, and updates all usages, mocks, and tests accordingly.
Initial implementation of MultiSelectWithSearch:
- Implement by survey and accessible prompters. They use the same internal func under the hood.
- Implement in `gh preview prompter` for initial testing and demonstration
- Implement interface changes across the codebase and mocks to satisfy compiler.
- Implement tests for new MultiSelectWithSearch prompter
