Create a suite of tests cases for integration tests

[0xedward]

These will be a list of test cases we will use once our testing infra is set up.

Since we are shimming DOMPurify, we won't need to repeat all the [test cases that DOMPurify has] here. Instead, it's probably more useful for us to take a test case from DOMPurify and create the respective HTML Sanitizer configuration object for the expected output for that respective test case. We want to make sure that configuration object behaves as the spec describes