Dimitris Athanasiou 4d6e037e90
[7.x][ML] Extract creation of DFA field extractor into a factory (#49315) (#49329)
This commit moves the async calls required to retrieve the components
that make up `ExtractedFieldsExtractor` out of `DataFrameDataExtractorFactory`
and into a dedicated `ExtractorFieldsExtractorFactory` class.

A few more refactorings are performed:

  - The detector no longer needs the results field. Instead, it knows
  whether to use it or not based on whether the task is restarting.
  - We pass more accurately whether the task is restarting or not.
  - The validation of whether fields that have a cardinality limit
  are valid is now performed in the detector after retrieving the
  respective cardinalities.

Backport of #49315
2019-11-20 10:02:42 +02:00
..