Allow non-null assertion operator on destructuring

まだ誰も着手していません。

### 🔍 Search Terms

destructuring non null assertion operator

### ✅ Viability Checklist

- [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code
- [x] This wouldn't change the runtime behavior of existing JavaScript code
- [x] This could be implemented without emitting different JS based on the types of the expressions
- [x] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
- [x] This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
- [x] This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

### ⭐ Suggestion

Allow the non-null assertion post-fix operator to be used in destructuring assignments

### 📃 Motivating Example

I was destructuring an object with a long name, but I couldn't do so because I also needed to assert it wasn't null, and this is not currently allowed
```ts
const { veryVeryVeryLongPropertyName! } = obj;
```
So I had to do this
```ts
const veryVeryVeryLongPropertyName = obj.veryVeryVeryLongPropertyName!;
```

### 💻 Use Cases

### What do you want to use this for?
To avoid having to specify the name twice

### What workarounds are you using in the meantime?
```ts
// Workaround: Short name
// Shortcoming: Not what I actually wanted to do
const temp = obj.veryVeryVeryLongPropertyName!;

// Workaround: Default `never` value
// Shortcoming: Verbose
const { veryVeryVeryLongPropertyName = undefined! } = obj;
```

issue の分割代入の例と、出力される JavaScript を変更してはならないという明示された制約から始めます。コンパイラーによる non-null assertions と分割代入の扱いを確認し、その後、必要な設計とテストを定めます。提案された構文が実行時の出力を変更せずに受理されれば完了です。

索引モデルが issue の本文から書いたものです。