Fully resolve aliases when checking symbol flags

[andrewbranch]

Fixes #44896
Fixes #50455

I actually don’t think this is a breaking change in any meaningful way. I do have one test that exhibits new errors, but the scenario is extremely contrived and didn’t exactly work before. Mostly, this removes false errors and false import elisions. The most visible and understandable example is the one from #44896:

// @filename: constants.ts
export const COFFEE = 0;
export const TEA = 1;


// @filename: drink.ts
export type Drink = 0 | 1;
export * as Drink from "./constants";


// @filename: index.ts
import { Drink } from "./drink";
// 👀 BEFORE: 'Drink' only refers to a type, but is being used as a value here
// 👍 AFTER: No error
const x: Drink = Drink.TEA;