fix: issue #2359 (#2368)

* Revert changes

* Unrap nested structure for doc code generation

* Revert changes

* Remove useless code

* Remove useless code

* Format code

tools/goctl/api/gogen/testdata/api_common.api

@@ -1,3 +0,0 @@
-type Common {
-	Some string `json:"some"` // some imported type
-}

tools/goctl/api/gogen/testdata/api_has_nested_type.api

@@ -1,48 +0,0 @@
-import "./api_common.api"
-type Resp {
-	R1 string `json:"r1"`
-	R2 bool   `json:"r2"`
-	R3 Common `json:"r3"`
-}
-type CommonResponse {
-	Code    int    `json:"code"` // 100 | 200
-	Message string `json:"message"`
-	Common
-	Response Resp `json:"response"`
-}
-
-type LoginResponseDto {
-	Id          string `bson:"_id" json:"id"`
-	Name        string `json:"name"`
-	AccessToken string `json:"accessToken"`
-}
-
-type UserCreateDto {
-	Id string `json:"id"`
-}
-type LoginRequest {
-	Username string `json:"username,optional"` // user name is optional
-	Password string `json:"password,optional"`
-}
-type LoginResponse {
-	*CommonResponse
-	Result *LoginResponseDto `json:"result"`
-}
-
-type UserCreateRequest {
-	Username string `json:"username,optional"` // some dsada
-	Password string `json:"password,optional"`
-}
-
-type UserCreateResponse {
-	*CommonResponse
-	Result *UserCreateDto `json:"result"` // result
-}
-
-service user-api {
-	@handler UserHandler
-	post /user/signin(UserCreateRequest) returns (UserCreateResponse)
-	
-	@handler LoginHandler
-	post /user/login(LoginRequest) returns (LoginResponse)
-}