[#1969] local_object_storage: Add a type for logical errors

All logic errors are wrapped in `logicerr.Logical` type and do not
affect shard error counter.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>

pkg/local_object_storage/util/logicerr/error.go

@@ -0,0 +1,21 @@
+package logicerr
+
+// Logical is a wrapper for logical errors.
+type Logical struct {
+	err error
+}
+
+// Error implements the error interface.
+func (e Logical) Error() string {
+	return e.err.Error()
+}
+
+// Wrap wraps arbitrary error into a logical one.
+func Wrap(err error) Logical {
+	return Logical{err: err}
+}
+
+// Unwrap returns underlying error.
+func (e Logical) Unwrap() error {
+	return e.err
+}