add Harmony message cut parameter to subset_params in service adapter

[danielfromearth]

Github Issue: #247

Description

Enable a Harmony message to specify the subsetter's cut parameter.

Overview of work done

This changes the service adapter so that it checks if extraArgs is present in the Harmony message, and if so the value of cut —  from the Harmony message's extraArgs — is passed along to the subset() function.

Overview of integration done

The integration tests were successful using SAMBAH service and TEMPO collection in local Harmony environment

PR checklist:

• Linted
• Updated unit tests
• Updated changelog
• Integration testing

See Pull Request Review Checklist for pointers on reviewing this pull request

[danielfromearth]

@jamesfwood, do you know how we can ensure that the integration tests on this feature branch PR use the recently updated, 0.19.0, Harmony schema?

[ank1m]

The integration tests were successful using SAMBAH service and TEMPO collection in local Harmony environment