Add a typescript linting rule to enforce commas between types

[supermii2]

Please include the steps to reproduce the bug.

TypeScript does not require a separator between types. However, for style and consistency, it should be enforced that there is always a comma separator between types

What was expected to happen?

An error should be thrown if the separator is missing.

Let's fix these using an eslint rule.

https://eslint.style/rules/ts/member-delimiter-style