[Bug] Newline completion items loss the attribute that is defined in unification stmt of the schema stmt

[Peefy]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

schema Metadata:
    name: str = name

schema Object:
    apiVersion: str
    kind?: str
    metadata: Metadata {name = "23"}

o = Object{
    
}

2. What did you expect to see? (Required)

The completion items is ["apiVersion", "kind", "metadata"]

3. What did you see instead (Required)

The completion items is ["apiVersion", "kind"] without the unification stmt in the schema stmt

4. What is your KCL components version? (Required)

v0.9.1