chore(all): wrap all sentinel errors

- Force to use `errors.Is` instead of `==` to compare errors

internal/httpserver/settings.go

@@ -91,11 +91,11 @@ func (s Settings) Validate() (err error) {
 	}
 
 	if s.Handler == nil {
-		return ErrHandlerIsNotSet
+		return fmt.Errorf("%w", ErrHandlerIsNotSet)
 	}
 
 	if s.Logger == nil {
-		return ErrLoggerIsNotSet
+		return fmt.Errorf("%w", ErrLoggerIsNotSet)
 	}
 
 	const minReadTimeout = time.Millisecond