refactor(interactive): Return the correct http code (#3700)

- Internally use `Result<>` to store the runtime error, and map the
error to http code at `admin_http_handler`.
- Extract commonly used code into utils function `http_utils.h`.

docs/flex/interactive/development/admin_service.md

@@ -1085,4 +1085,30 @@ To start admin service in development, use the command line argument `--enable-a
 The Compiler service could be started as a subprocess of the AdminService. This ensures that when switching graphs in the AdminService, the Compiler service also switches to the corresponding graph's schema. This is the default behavior in the current Interactive.
 
 ```bash
-./bin/interactive_server -c ${ENGINE_CONFIG} -w ${WORKSPACE} --enable-admin-service true --start-compiler true
+./bin/interactive_server -c ${ENGINE_CONFIG} -w ${WORKSPACE} --enable-admin-service true --start-compiler true
+```
+
+
+## Http error code
+
+Internally we use [`StatusCode`](https://github.com/alibaba/GraphScope/blob/main/flex/utils/result.h) to record the runtime errors.
+The mapping between statusCode and http code is shown in the following table.
+
+| Code                                | HTTP Code   |
+| ----------------------------------- | ----------- |
+| gs::StatusCode::OK                  | 200         |
+| gs::StatusCode::InValidArgument     | 400         |
+| gs::StatusCode::UnsupportedOperator | 400         |
+| gs::StatusCode::AlreadyExists       | 409         |
+| gs::StatusCode::NotExists           | 404         |
+| gs::StatusCode::CodegenError        | 500         |
+| gs::StatusCode::UninitializedStatus | 500         |
+| gs::StatusCode::InvalidSchema       | 400         |
+| gs::StatusCode::PermissionError     | 403         |
+| gs::StatusCode::IllegalOperation    | 400         |
+| gs::StatusCode::InternalError       | 500         |
+| gs::StatusCode::InvalidImportFile   | 400         |
+| gs::StatusCode::IOError             | 500         |
+| gs::StatusCode::NotFound            | 404         |
+| gs::StatusCode::QueryFailed         | 500         |
+| default                             | 500         |