- Add `get_location` endpoint to retrieve location information with optional upstream inclusion.
- Introduce `get_proxy_list` and `get_proxy` endpoints for listing and retrieving proxy hosts.
- Implement `remove_location` and `remove_proxy` endpoints for deleting locations and proxy hosts respectively.
- Add `update_location` and `update_proxy` endpoints for modifying existing locations and proxy hosts.
- Create response structures for location and proxy host information.
- Implement tests for all new endpoints to ensure correct functionality and error handling.
- Added `ProxyHostInfo`, `ProxyHostCreateInfo`, and `UpdateProxyHostInfo` structs to manage proxy host data.
- Created `ProxyService` and `ProxyServiceImpl` for handling proxy host operations including create, read, update, and delete.
- Implemented `LocationService` and `LocationServiceImpl` for managing locations associated with proxy hosts.
- Introduced database transaction handling for creating proxies and locations.
- Added tests for all service methods to ensure functionality and correctness.
