Delta Lake metadata query detection logic should be moved into DeltaProvider

[jlowe]

Is your feature request related to a problem? Please describe.
Currently Delta Lake metadata query detection searches the entire query plan for nodes matching the rule, but this is wasteful when Delta Lake isn't available in the runtime environment.

Describe the solution you'd like
This logic should be moved to the code specific to supporting Delta Lake and the predicate function exposed through something like ExternalSource.