[#240] logs: Move log messages to constants

Drop duplicate entities.
Format entities.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/local_object_storage/blobstor/exists.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/pkg/tracing"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
@@ -57,7 +58,7 @@ func (b *BlobStor) Exists(ctx context.Context, prm common.ExistsPrm) (common.Exi
 	}
 
 	for _, err := range errors[:len(errors)-1] {
-		b.log.Warn("error occurred during object existence checking",
+		b.log.Warn(logs.BlobstorErrorOccurredDuringObjectExistenceChecking,
 			zap.Stringer("address", prm.Address),
 			zap.String("error", err.Error()))
 	}