fix: inherit App error catalogs on generated routes without local errors

examples/contracts/errorInheritance.api

@@ -0,0 +1,41 @@
+syntax = "v1"
+
+// Errors are registered once in Go with omni.WithErrors.
+response CommonResponse (
+    codeType: int32
+    successCode: 0
+    errorCode: 9999
+    body: {"code": "${code}", "msg": "${message}", "data": "${data}"}
+    dataMode: always
+)
+
+type CheckRequest {
+    Kind string `form:"kind,optional"`
+}
+type CheckResponse {
+    OK bool `json:"ok"`
+}
+
+@server (
+    group: account
+    response: CommonResponse
+)
+service inherited-errors-api {
+    @handler plain
+    get /plain (CheckRequest) returns (CheckResponse)
+
+    @response raw
+    @handler raw
+    get /raw (CheckRequest) returns (CheckResponse)
+
+    @errors none
+    @handler cleared
+    get /cleared (CheckRequest) returns (CheckResponse)
+
+    @handlerMode manual
+    @body (mode: raw
+           maxBytes: 64)
+    @produces "text/plain"
+    @handler bounded
+    post /bounded
+}