ELG platform (first release)

Summary
Software code and report. The first release of the platform will include the backend components required for the operation of the catalogue, i.e., the user management component (part of T2.8), components supporting documentation, uploading, storing and downloading of all resource types (tools and services, datasets, etc.), and APIs required for interacting with other layers (T2.3 and T2.4). An alpha release will be made internally available at M14 for testing with the upload of a limited sets of tools and services (D4.1) and datasets (WP5). D2.4 will introduce the platform, and include the first version of the guidelines on its use and provision of resources, instructions for containerisation and invoking of remotely accessible web services.