[#139] test: Add test storage implementation

This aims to reduce the usage of chmod hackery to induce or simulate
OS-related failures.

Signed-off-by: Alejandro Lopez <a.lopez@yadro.com>

cmd/frostfs-lens/internal/writecache/root.go

@@ -1,6 +1,8 @@
 package writecache
 
 import (
+	"os"
+
 	common "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-lens/internal"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
 	"github.com/spf13/cobra"
@@ -24,7 +26,7 @@ func init() {
 }
 
 func openWC(cmd *cobra.Command) *bbolt.DB {
-	db, err := writecache.OpenDB(vPath, true)
+	db, err := writecache.OpenDB(vPath, true, os.OpenFile)
 	common.ExitOnErr(cmd, common.Errf("could not open write-cache db: %w", err))
 
 	return db