Add metadata interface

[polaya07]

This is a pull request to add the metadata interface that generates the graph representation of the different workflows based on the metadata.

• To run, execute the Fine-grained_metadata_interface.ipynb. You will find the instructions to interactively visualize the components of the workflow based on the metadata.
• There is a folder Examples_of_metadata where you will find two sets of metadata that can be loaded in the interface