Aligning public data with user-defined season: add an attribute to store the shift

[cbutsko]

When users query public extractions parquet and provide their own processing period, we need to align existing extractions with the user-proposed season and make sure that the label (represented by the valid_date) is still preserved in the selected period.

While the current version of code is already doing that (refer to this part), it would be nice to add more context for the user and include the actual shift that has been made with the respect to the actual label position.

To do:

• add an attribute to the resulting dataframe of the query_public_extraction function that preserves information about the shift
• add a logger message/warning to the user that notifies the user about the number of samples where the shift was larger than a threshold
• define the acceptable threshold of the shift