FS-3629: Add shared answer display class

[tferns]

Description

• Adds a python directory with python specific tools for our fork of the digital-form-builder
• Add a github action to run tests on the python specific stuff, and upload the changes to PyPi
• We need to bump the version manually, I think we should keep it this way - so we're forced to do semantic versioning
• Add pre-commit hooks related to python, README.md related to the python dir (writing better version atm)
• Add the concept of an AnswerDisplayer abstract class
  • Each currently used component has a concrete implementation, with test coverage for how it will display
  • There are three methods it supports (at the moment, but we can add more) CSV, TXT, PDF
  • When using this to render the CSV, TXT & PDF, these implementations may change!
• dictionaries.py holds relevant mappings that may be used on downstream integrations to map answers properly, exactly how this is used and the structure may change once the work implementing downstream is in place.

Note: Some components need to handle back-wards compatibility to how the component used to render, i.e MultiInputFieldDisplayer has both a legacy and new way of displaying. Also - when some components are embedded in a MultiInputField component, their structure they're saved as is different, so some also have a implementation specifically for that scenario, i.e. UkAddressField and MonthYearField.

Package

Available on PyPi here: https://pypi.org/project/funding-service-design-digital-form-builder-tools/0.0.1/

When merging to main, if the version is bumped (it's bumped to 0.0.2 here) - it will update on PyPi.

[Adam-W1]

lovely docs @tferns 👍

[Adam-W1]

great use of ABC

[adamdavies1]

LGTM