chore: switch database engine to sqlite (fixes #9954) (#9965)

Switch the database from LevelDB to SQLite, for greater stability and
simpler code.

Co-authored-by: Tommy van der Vorst <tommy@pixelspark.nl>
Co-authored-by: bt90 <btom1990@googlemail.com>

lib/versioner/simple.go

@@ -41,7 +41,7 @@ func newSimple(cfg config.FolderConfiguration) Versioner {
 	s := simple{
 		keep:            keep,
 		cleanoutDays:    cleanoutDays,
-		folderFs:        cfg.Filesystem(nil),
+		folderFs:        cfg.Filesystem(),
 		versionsFs:      versionerFsFromFolderCfg(cfg),
 		copyRangeMethod: cfg.CopyRangeMethod.ToFS(),
 	}