Show warning when using a catch-all pattern with dataset factories

[ankatiyar]

Description

Users can register default datasets with dataset factories (#2423) by adding a catch-all pattern:

"{default}":
  filepath: data/01_raw/{default}.csv
  type: CSVDataSet

Add a warning when this is catch-all pattern is used.

Context

From User research #2602

2. There should be a warning about the catch-all pattern that replaces default dataset creation

5 users mentioned this explicitly:

"if you did a dataset that replaced all the memory dataset, would we get like a warning or an error or something?"

"Maybe it'll be nice to, for users if they define something like that, to give them like warning or even to give them a prompt that they made or ask them if it's, if it's expected. Because I guess that that will be the, the first mistake everyone makes when they start working with the feature."

[ankatiyar]

Closed by #2774