createOperations(): prefer simpler pipelines / affects WGS 84 to GDA94/GDA2020 #3248
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Prior to this change, transforming to WGS 84 to GDA2020 used in priority
transformation EPSG:9690 ("WGS 84 to GDA2020 (3)"), which is a Helmert
transformation assuming WGS 84 ~= GDA94.
But transforming from GDA2020 to WGS 84 used EPSG:8450 "GDA2020 to WGS
84 (2)" which is a no-op.
Both have the same advertized accuracy 3m
Similar case for WGS 84 <--> GDA94.
This non symetric behaviour is clearly non-desirable in scenarios where
data is transformed back and forth. I believe it is preferable to use in
that situation of transformations with the same accuracy to use the one
that involves the less transformation steps, ie the no-op one.
Seen when checking #2348 again
(whose bulk issues happens to have been fixed by other previous commits)
CC @nyalldawson