add interactive mode

when run with no args, interactive mode is launched
files in trash are listed, select files, and use r/c to restore/clean them

internal/modes/modes.go

@@ -0,0 +1,28 @@
+package modes
+
+type Mode int
+
+const (
+	Trashing Mode = iota + 1
+	Listing
+	Restoring
+	Cleaning
+	Interactive
+)
+
+func (m Mode) String() string {
+	switch m {
+	case Trashing:
+		return "Trashing"
+	case Listing:
+		return "Listing"
+	case Restoring:
+		return "Restoring"
+	case Cleaning:
+		return "Cleaning"
+	case Interactive:
+		return "Interactive"
+	default:
+		return "0"
+	}
+}