[BEAM-9622] Add Python SqlTransform test that joins tagged PCollections (#11684)
[BEAM-9622] Add Python SqlTransform test that joins tagged PCollections (#11684)

* Add test that joins tagged pcollections

* remove unnecessary backticks
chamikaramj/beam,chamikaramj/beam,lukecwik/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,chamikaramj/beam,chamikaramj/beam,robertwb/incubator-beam,apache/beam,robertwb/incubator-beam,chamikaramj/beam,apache/beam,apache/beam,chamikaramj/beam,chamikaramj/beam,lukecwik/incubator-beam,chamikaramj/beam,lukecwik/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,iemejia/incubator-beam,robertwb/incubator-beam,robertwb/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,apache/beam,apache/beam,lukecwik/incubator-beam,robertwb/incubator-beam,robertwb/incubator-beam,apache/beam,robertwb/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,apache/beam,apache/beam,chamikaramj/beam,apache/beam,chamikaramj/beam,robertwb/incubator-beam,apache/beam,apache/beam,iemejia/incubator-beam