Creating draft DOI for folder when folder is published

[csc-jm]

Description

This PR enables requesting DataCite REST API and creating a draft DOI for a folder when the folder is published via publish_folder endpoint. PR also includes a mock DOI app, that is meant to resemble the response from DataCite REST API.

Further development is required for full functionality to complete the DOI creation workflow.

Related issues

Partially fixes #155

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Changes Made

• added a doi helper class which can request a draft DOI creation from DataCite API
• altered publish_folder endpoint so that extraInfo containing the DOI data is added upon publishing
• added datePublished key to folders which takes in the date/time, when folder is published
• created a mock web app, which would act similarly to DataCite REST API
• added configuration values, and the mock app to docker compose file
• added unit test class for DOIHandler and altered integration tests to work with no feature

Testing

• Unit Tests
• Integration Tests

Mentions

The DOIHandler was composed similarly to SDA-orchestrator

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publishing a real DOI, will come in a follow-up PR