[misc] Separate shared code dependencies (#4288)

* Separate shared code dependencies

* Fix import

* Test respective shared code

* Update openapi ref

* Fix test

* Fix test path

shared/relay/tls/server_prod.go

@@ -0,0 +1,17 @@
+//go:build !devcert
+
+package tls
+
+import (
+	"crypto/tls"
+	"fmt"
+)
+
+func ServerQUICTLSConfig(originTLSCfg *tls.Config) (*tls.Config, error) {
+	if originTLSCfg == nil {
+		return nil, fmt.Errorf("valid TLS config is required for QUIC listener")
+	}
+	cfg := originTLSCfg.Clone()
+	cfg.NextProtos = []string{nbalpn}
+	return cfg, nil
+}