feat: custom json marshaling implementation, replace json and yaml library (#89)

* chore: replace gopkg.in/yaml.v3 vs goccy/go-yaml; replace encoding/json with bytedance/sonic

* fix: yaml unmarshal panic

* feat: custom json marshaler implementation

* chore: fix import and err marshal handling

---------

Co-authored-by: yusing <yusing@6uo.me>

agent/pkg/handler/check_health_test.go

@@ -1,7 +1,6 @@
 package handler_test
 
 import (
-	"encoding/json"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -9,6 +8,8 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/stretchr/testify/require"
 	"github.com/yusing/go-proxy/agent/pkg/agent"
 	"github.com/yusing/go-proxy/agent/pkg/handler"