Enables more flexible writer signature in TensorBoardHandler

[YuanTingHsieh]

Is your feature request related to a problem? Please describe.
I want to use the TensorBoardHandler but my custom writer would requires more context from engine.

The logic in this line https://github.com/Project-MONAI/MONAI/blob/dev/monai/handlers/tensorboard_handlers.py#L224
required writer to have this fixed signature.

I would like to implement a custom writer which needs information from the engine, but can still reuse the same logic to get loss and metric of the default logger.