Supporting connection graphql directives on inline fragments

Currently the connection graphql directives (e.g. `@appendNode`, `@appendEdge`, etc...) can only be used on a field object but not an inline fragment. The proposal here is to expand. the usage of the directives to also work on inline fragments. The use case for this is when you have a union type:

Example:

```
mutation {
commentCreate(...) {
comment {
... on Comment @appendEdge(...) {
id
}
... on CommentErrors {
error
}
}
}
}
```