Merge #472

472: feat(http): Distinct app and internal error codes in the handleError function r=48d90782 a=48d90782

This PR introduces distinct error codes for the app and internal RR errors.
Errors: 
```go
roadrunner.ErrNoAssociatedPool
roadrunner.ErrAllocateWorker
roadrunner.ErrWorkerNotReady
roadrunner.ErrEmptyPayload
roadrunner.ErrPoolStopped
roadrunner.ErrWorkerAllocateTimeout
roadrunner.ErrAllWorkersAreDead
```
now associated with the internal error codes. All other errors are application errors.
Some types of errors are impossible to distinguish in the RR1, for example `json.Unmarshall` internal error or similar.
The `.rr.yaml` now contain two more options for the errors.
```yaml
http:
    internalErrorCode: 502,
    appErrorCode: 502
```
Default behavior unchanged (500 error code as before), but now might be overridden.
closes #471 

Co-authored-by: Valery Piashchynski <[email protected]>

4 files changed, 9 insertions, 5 deletions

diff --git a/service/limit/config.go b/service/limit/config.go
index 203db11b..7a56280d 100644
--- a/service/limit/config.go
+++ b/service/limit/config.go
@@ -1,9 +1,10 @@
 package limit
 
 import (
+	"time"
+
 	"github.com/spiral/roadrunner"
 	"github.com/spiral/roadrunner/service"
-	"time"
 )
 
 // Config of Limit service.
diff --git a/service/limit/config_test.go b/service/limit/config_test.go
index c79836b8..1f121bc5 100644
--- a/service/limit/config_test.go
+++ b/service/limit/config_test.go
@@ -1,11 +1,12 @@
 package limit
 
 import (
+	"testing"
+	"time"
+
 	json "github.com/json-iterator/go"
 	"github.com/spiral/roadrunner/service"
 	"github.com/stretchr/testify/assert"
-	"testing"
-	"time"
 )
 
 type mockCfg struct{ cfg string }
diff --git a/service/limit/controller.go b/service/limit/controller.go
index 24a158f7..b4a1c25f 100644
--- a/service/limit/controller.go
+++ b/service/limit/controller.go
@@ -2,9 +2,10 @@ package limit
 
 import (
 	"fmt"
+	"time"
+
 	"github.com/spiral/roadrunner"
 	"github.com/spiral/roadrunner/util"
-	"time"
 )
 
 const (
diff --git a/service/limit/state_filter.go b/service/limit/state_filter.go
index cd2eca94..4e05769a 100644
--- a/service/limit/state_filter.go
+++ b/service/limit/state_filter.go
@@ -1,8 +1,9 @@
 package limit
 
 import (
-	"github.com/spiral/roadrunner"
 	"time"
+
+	"github.com/spiral/roadrunner"
 )
 
 type stateFilter struct {