Modify IO module to retrieve source data from data pipeline

[andyb96247]

Incorporate calls to the C++ version the data pipeline api to interface with the local copy of data downloaded from the external repository.

Things to achieve:

• [x] Create new data pipeline class to mirror existing IO
• [x] Port Fixed Parameters to data pipeline
• [x] Update tests for Fixed Parameters / data pipeline
• [x] Start to port other data types
• [x] Update README.me to reflect data pipeline workflow
• [ ] Fix CI actions to be able to find and use data pipeline API / python

[github-actions[bot]]

Heads up @thibaud-porphyre @peter-t-fox - the "Covid19_EERAModel" label was applied to this issue.