[Value Classes] Collection equality

The draft for value classes was just added by @munificent and I noticed that it didn't seem to mention collection equality (correct me if I'm wrong). I know the spec was just added but I figured I'd open an issue to get dialogue on this topic.

```dart
value class Company {
String name;
List employees;

Company(this.name, this.employees);
}
```

If I were to create instances like so:

```dart
final company1 = Company('Foo', ['bar']);
final company2 = Company('Foo', ['bar']);
```

Would these be equal even though they're not const?

Also will there be deep `Map` equality?

Start with the value classes draft referenced in the issue and review how equality is specified for fields containing List and Map values. Done means reaching and recording a clear decision about non-const collection equality and deep Map equality in the value-class specification.

Written by the indexing model from the issue text.