fix: read fieldType from currently processed type

[Sekhmet]

When using nested where filter we should read field return type from that nested type, not top-level type.

Test plan

• Same as https://github.com/checkpoint-labs/checkpoint/pull/319
• Plus run following query that was broken:

{
    proposals(
    where: {
      cancelled: false
      space_in: [
        "0x03ced313394107c43a2f36b63262c00a6422231ac229dc4cedd0d9928d8c3c5f"
      ]
      metadata_: { title_contains_nocase: "" }
    }
  ) {
    id
  }
}