Build a spatial interpolation map based on the Inverse Distance Weighting technique. The function EEAaq_idw_map requires as input a EEAaq_taggr_df or a EEAaq_taggr_df_sfc class object and produces a spatial interpolation map. Depending on the time frequency of the aggregation, multiple maps are generated, one for each timestamp. Interpolation maps may be exported as pdf, jpeg, png, gif and html.