* Splits the existing script into multiple classes
* Adds command for generating IntermediateDB schema (`migrations/bin/cli schema generate`)
* Changes the syntax of the IntermediateDB schema config
* Adds validation for the schema config
* It uses YAML schema aka JSON schema to validate the config file
* It generates the SQL schema file and Ruby classes for storing data in the IntermediateDB
* Updates GitHub Action for migrations
* Rubocop: Always `EnforcedShorthandSyntax` for hashes in the `migrations` directory
* Automatically load all available converter steps
* Enable YJIT at runtime, if available
* Progressbar shows skipped records and other small improvements
* Updates GitHub Actions
* Switches from `bundler/inline` to an optional group in the `Gemfile` because the previous solution didn't work well with rspec
* Adds the converter framework and tests
* Allows loading private converters (see README)
* Switches from multiple CLI tools to a single CLI
* Makes DB connections reusable and adds a new abstraction for the `IntermediateDB`
* `IntermediateDB` acts as an interface for IPC calls when a converter steps runs in parallel (forks). Only the main process writes to the DB.
* Includes a simple example implementation of a converter for now.
