Data Retriever: Add support for more raw data formats

The Data Retriever is a package manager for data. The Data retriever automatically finds, downloads and pre-processes publicly available datasets and it stores these datasets in a ready-to-analyse state. The Data Retriever handles tabular data and spatial data forms. The goal of the project is to add support that will enable the Data Retriever platform to have the capability of ingesting other forms of raw data. The project will introduce the support for raw data formats of XML, JSON, NetCDF, HDF, Excel, SQlite and Geojson data sources.