add pub access modifier to publicly used struct fields (#263)

Author: ttytm

api/api.v

@@ -1,16 +1,19 @@
 module api
 
 pub struct ApiErrorResponse {
+pub:
 	success bool
 	message string
 }
 
 pub struct ApiResponse {
+pub:
 	success bool
 	message string
 }
 
 pub struct ApiSuccessResponse[T] {
+pub:
 	success bool
 	result  T
 }