feat: migrate all remaining modules from rainyun-go-sdk

- domain(24), product(8), rbm(10), rca(21), rgs(38), ros(19),
  ssl(5), user(10), workorder(11), public remaining 5
- split nested response structs into reusable named types
- rgs reuses rcs request/response types
- fix source bugs: malformed paths, resp vs &resp, missing bodies
- register all 11 services in sdk.New

apis/user/client.go

@@ -0,0 +1,11 @@
+package user
+
+import "github.com/XingfenD/rainyun_api_go_sdk/apis"
+
+type UserService struct {
+	client *apis.RyClient
+}
+
+func NewUserService(c *apis.RyClient) *UserService {
+	return &UserService{client: c}
+}