[MAJOR] Many changes for Conformity 2.0 (WIP)

[sethbrite]

Conformity 2.0 will be the next major release of Conformity. The primary goals we aim to achieve with this major version are:

• More intuitive fields and APIs
• Increased composability
• Easier custom field creation and extension
• Richer validation information
• Removal of unnecessary dependencies
• Easy migration from 1.x to 2.0
• Integration with Python static analysis tools (e.g., Mypy)

To facilitate migration from 1.x to 2.0, we have deprecated (not removed) many common 1.x APIs and fields. As such, most projects currently utilizing Conformity 1.x should continue to work without modifications upon upgrading to 2.0. However, breaking changes do exist. These will be detailed in a soon-to-be-written migration document.