Mirror the Android profile manager in the iOS gomobile binding so the
core's ID-based profilemanager.ServiceManager owns profile state on iOS
too, instead of a parallel Swift reimplementation.
Adds client/ios/NetBirdSDK/profile_manager.go (//go:build ios): an
ID-based ProfileManager wrapping ServiceManager with iOS-specific path
handling (default profile at the container-root netbird.cfg, others as
profiles/<id>.json) and a gomobile-friendly API: List/Add/Switch/Rename/
Logout/Remove plus active config/state path accessors. The default
profile keeps the reserved "default" id and is never assigned a hex id.