Issue500 update data manager

[EttoreZ]

This PR addresses #500, a warning was added to the data/data_manager.py script if any of the weather variables present in data/categories.json is missing from wrapped.fum/resources/weather.csv.

[dhblum]

@EttoreZ I think this functionality should go in the method save_data_and_jsons since that is invoked when the csvs are moved to the FMU when compiling the test case and is when other similar warnings are shown to a test case developer if there are issues with the different files.

load_data_and_jsons is called when the test case docker container is deployed and the warning message will be lost among alot of other container deployment messages, not known to a typical boptest user (who is not a test case developer), and may not be displayed at all if the container is deployed in the background or a remote server (i.e. on aws).

[EttoreZ]

@dhblum thank you for the comments, they all make sense.

• I moved the warning to the method _append_csv_data within save_data_and_jsons , which is where the .csv files are checked.
• I updated the release notes according to the suggestion.