Use dataflow analysis to detect `qubitMeasurementFeedback` flag

[1tnguyen]

We should investigate using dataflow analysis [pass] as a systematic way to detect mid-circuit measurement and fast feedback conditionals in the IR.

          IMO, this analysis shouldn't really be done on the AST.
          Can you create another issue to replace this ad hoc pattern matching with a dataflow analysis? (We need it for C++ as well.)

Originally posted by @schweitzpgi in #1619 (comment)