`\N{name}` needs to use fuzzy matching

The name in a `\N{...}` block should use fuzzy matching instead of exact equality.

```swift
"👩‍👩‍👧‍👦".contains(/(?u).\N{ZERO WIDTH JOINER}/)   // true
"👩‍👩‍👧‍👦".contains(/(?u).\N{ZeroWidthJoiner}/)     // false, should be true
```