* 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
* Moves existing files around. All essential scripts are in `migrations/bin`, and non-essential scripts like benchmarks are in `migrations/scripts`
* Dependabot configuration for migrations-tooling (disabled for now)
* Updates test configuration for migrations-tooling
* Shorter configuration for intermediate DB for now. We will add the rest table by table.
* Adds a couple of benchmark scripts
* RSpec setup especially for migrations-tooling and the first tests
* Adds sorting/formatting to the `generate_schema` script
