This includes:

1. Split the implementation into multiple files
2. spirv-fuzz: Unable to create certain types of queries in the fact manager #3550
3. Assert that we are adding valid facts (e.g. PointeeValueIsIrrelevant is applied to the pointer).
4. Refactor existing transformations to add facts after analyses have been invalidated.
5. AddInitialFacts function.
6. Refactor tests into separate files