Iterative writes

Similarly to the reason `conditionalWrite` was introducted, it would be really nice if we were not forced to break the chain and introduce a `for-of` loop with a single `writeLine` call.

Something along the lines of the following would be great.

```ts
const indexes = [5, 9, 10, 15, 17]

writer
.writeLine(`return [`)
.iterateWriteLine(indexes, index => `this.array[${index}],`)
.writeLine(`]`)
```