General quality review

[james-whiteside]

What is the goal of this PR?

TypeDB Bio previously did not load data properly resulting in a large number of data errors like:

• Multiple entities with the same identifiers.
• Multiple relations between the same roleplayers.
• String attributes containing multiple unnormalised values as long strings.
• Empty string attributes.
• Incorrect identifiers resulting from bad processing.

In addition to solving these errors, this PR streamlines the schema to remove types that are not instantiated by the loaders incorporated so far, reviews the type hiercharchy to better utilise subytping, reviews the rules to provide more powerful insights, and makes several general improvements to code quality and user outputs.

[james-whiteside]

Still to do:

• Update readme.
• Fix broken test.