Handle different dataset types in a better way

[antonymilne]

The code that handles different datasets types uses the full to the dataset class, like this:

kedro-viz/package/kedro_viz/models/graph.py

Lines 492 to 497 in 21f4534

	def is_metric_node(self):
	"""Check if the current node is a metrics node."""
	return (
	self.dataset_type
	== "kedro.extras.datasets.tracking.metrics_dataset.MetricsDataSet"
	)

This is quite verbose, awkward and also fragile, because if the definition moves in kedro (which it will do when we move to kedro-dataset). Let's come up with a better system for it, e.g. just using type(dataset).__qualname__ without including the module path.

Possible gotchas:

• kedro-viz needs to work without e.g. the underlying dependencies for e.g. kedro.extras.datasets.matplotlib.matplotlib_writer.MatplotlibWriter. This might be why it's done the way it is currently (string matching) rather than using isinstance
• need to think about what to do if __qualname__ is not unique, e.g. in the case of json.JSONDataSet vs. plotly.JSONDataSet

[rashidakanchwala]

I agree, json.JSONDataset, tracking.JSONDataSet, and plotly.JSONDataSet -- can we have more unique qualname_

[rashidakanchwala]

This is solved now. so we can close it :)

[tynandebold]

Improved via #1214.