Promote keyRetrieversSetter to public KeyManager and lift
keychainPasswordSetter from browser_darwin.go into browser.go as
KeychainPasswordReceiver. Engines already implement these methods;
only type-assertion sites switch to the public interface names.
* refactor: Refactor package names and imports for better code organization.
* refactor: Package imports and variable types for consistency
* chore: Disable unused-parameter rule in revive.
* refactor: Refactor and organize data extraction and browserdata parse.
* fix: rename wrong error message info
Roger