Support for h5web #208
Description
h5web is a nice set of dataset visualizers that works on top of h5grove, a server for HDF5 files that implements a REST API based on an OpenAPI specification. As the current OpenAPI 3.0.0 specs are quite simple (just 5 entry points), it would be nice to implement them inside Caterva2 (ideally under an /openapi namespace), so that we can use it directly from either an standalone h5web or a Caterva2 resident one.