Normalize union/intersection type combinations

[Anders Hejlsberg (ahejlsberg)]

With this PR we normalize combinations of intersection and union types based on the distributive property of the & type operator over the | type operator. Specifically, because X & (A | B) is equivalent to X & A | X & B, we can transform intersection types with union type constituents into equivalent union types with intersection type constituents and thus ensure that union types are always at the top level in type representations and equivalent ways of writing the same type are treated identically.

interface A { a: string }
interface B { b: string }
interface C { c: string }
interface D { d: string }

// Identical ways of writing the same type
type X1 = (A | B) & (C | D);
type X2 = A & (C | D) | B & (C | D);
type X3 = A & C | A & D | B & C | B & D;

In the example above, X1, X2, and X3 are all identical types that reference the normalized form A & C | A & D | B & C | B & D.

Fixes #9919.

[Nathan Shively-Sanders (sandersn)]

One question about isRelatedTo and a possible improvement for reporting errors with intersections of boolean.

[Nathan Shively-Sanders (sandersn)]

Is there some way to present this error as number & boolean still? I feel like the distributed form is unexpected here.