Given a database, provide a way to check if a resharding operation is ongoing for an owned collection: this can be achievable by adding a field to DatabaseType.

In v5.0, only one resharding operation is expected to be executed in the whole cluster. However, it would be nice to provide a counter - instead of a simple flag - in order to already prepare metadata for the future.

The counter in config.databases entries is expected to keep track of the number of resharding operations and it should be incremented here and decremented here