Re-enabled the Renderer object's occlusion queries and linked them
to the queries in the query pool. Removed the old Query structure.

Passes all tests in:
Tests: dEQP-VK.query_pool.*

Note: The dEQP-VK.query_pool.*_discard tests currently fail as discard
      appears to disable the occlusion queries. Will fix in next cl.

Bug b/129706526

Change-Id: I937dcf64d2990758d31a1ed6a13af5cf9f0a627b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28288Tested-by: Alexis Hétu <sugoi@google.com>
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>