[management,client] Make DNS ForwarderPort Configurable & Change Well Known Port (#4479)

makes the DNS forwarder port configurable in the management and client components, while changing the well-known port from 5454 to 22054. The change includes version-aware port assignment to ensure backward compatibility.

- Adds a configurable `ForwarderPort` field to the DNS configuration protocol
- Implements version-based port computation that returns the new port (22054) only when all peers support version 0.59.0 or newer
- Updates the client to dynamically restart the DNS forwarder when the port changes

client/internal/routemanager/dnsinterceptor/handler.go

@@ -24,8 +24,8 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager/common"
 	"github.com/netbirdio/netbird/client/internal/routemanager/fakeip"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
-	"github.com/netbirdio/netbird/shared/management/domain"
 	"github.com/netbirdio/netbird/route"
+	"github.com/netbirdio/netbird/shared/management/domain"
 )
 
 const dnsTimeout = 8 * time.Second
@@ -257,7 +257,7 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		r.MsgHdr.AuthenticatedData = true
 	}
 
-	upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), dnsfwd.ListenPort)
+	upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), dnsfwd.ListenPort())
 	ctx, cancel := context.WithTimeout(context.Background(), dnsTimeout)
 	defer cancel()