Add netstack support for the agent to run it without privileges.
- use interface for tun device
- use common IPC for userspace WireGuard integration
- move udpmux creation and sharedsock to tun layer
* starting engine by passing file descriptor on engine start
* inject logger that does not compile
* logger and first client
* first working connection
* support for routes and working connection
* small refactor for better code quality in swift
* trying to add DNS
* fix
* updated
* fix route deletion
* trying to bind the DNS resolver dialer to an interface
* use dns.Client.Exchange
* fix metadata send on startup
* switching between client to query upstream
* fix panic on no dns response
* fix after merge changes
* add engine ready listener
* replace engine listener with connection listener
* disable relay connection for iOS until proxy is refactored into bind
* Extract private upstream for iOS and fix function headers for other OS
* Update mock Server
* Fix dns server and upstream tests
* Fix engine null pointer with mobile dependencies for other OS
* Revert back to disabling upstream on no response
* Fix some of the remarks from the linter
* Fix linter
* re-arrange duration calculation
* revert exported HostDNSConfig
* remove unused engine listener
* remove development logs
* refactor dns code and interface name propagation
* clean dns server test
* disable upstream deactivation for iOS
* remove files after merge
* fix dns server darwin
* fix server mock
* fix build flags
* move service listen back to initialize
* add wgInterface to hostManager initialization on android
* fix typo and remove unused function
* extract upstream exchange for ios and rest
* remove todo
* separate upstream logic to ios file
* Fix upstream test
* use interface and embedded struct for upstream
* set properly upstream client
* remove placeholder
* remove ios specific attributes
* fix upstream test
* merge ipc parser and wg configurer for mobile
* fix build annotation
* use json for DNS settings handover through gomobile
* add logs for DNS json string
* bring back check on ios for private upstream
* remove wrong (and unused) line
* fix wrongly updated comments on DNSSetting export
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Co-authored-by: Maycon Santos <mlsmaycon@gmail.com>