fix: DateCardCellState date formatting (#3387)

* fix: DateCardCellState date formatting

* refactor: use string interpolation

frontend/appflowy_flutter/lib/plugins/database_view/widgets/card/bloc/date_card_cell_bloc.dart

@@ -80,7 +80,11 @@ class DateCardCellState with _$DateCardCellState {
 String _dateStrFromCellData(DateCellDataPB? cellData) {
   String dateStr = "";
   if (cellData != null) {
-    dateStr = "${cellData.date} ${cellData.time}";
+    if (cellData.includeTime) {
+      dateStr = '${cellData.date} ${cellData.time}';
+    } else {
+      dateStr = cellData.date;
+    }
   }
   return dateStr;
 }