refact: some refactoring to the http proxy code

session/modules/http_proxy_js_request.go

@@ -0,0 +1,19 @@
+package session_modules
+
+type JSHeader struct {
+	Name  string
+	Value string
+}
+
+type JSRequest struct {
+	Method   string
+	Version  string
+	Path     string
+	Hostname string
+	Headers  []JSHeader
+	Body     string
+}
+
+func (j *JSRequest) ReadBody() string {
+	return "TODO: read body"
+}