feat: support `CreateEnumStmt`

[cvng]

What kind of change does this PR introduce?

feat: support CreateEnumStmt

What is the current behavior?

Parser panics

What is the new behavior?

[2023-12-13T14:27:17Z DEBUG parser::codegen::tests] pg_query_root: Some(
        CreateEnumStmt(
            CreateEnumStmt {
                type_name: [
                    Node {
                        node: Some(
                            String(
                                String {
                                    sval: "status",
                                },
                            ),
                        ),
                    },
                ],
                vals: [
                    Node {
                        node: Some(
                            String(
                                String {
                                    sval: "open",
                                },
                            ),
                        ),
                    },
                    Node {
                        node: Some(
                            String(
                                String {
                                    sval: "closed",
                                },
                            ),
                        ),
                    },
                ],
            },
        ),
    )

Additional context

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