[vscode-graphql-syntax] The types of a union that has a directive are coloured like a directive


The types of `union1a` and `union2a` are coloured the same as the directive in the union. Instead, I would expect them to remain coloured as they are in `union1b` and `union2b`.

```gql
union union1a @deprecated = Int
union union1b = Int
union union2a @deprecated = Int | Float
union union2b = Int | Float
```