add typed/racket/async-channel
Make interning work on Rep-seq for Reps with complicated fields.

This gives ~3% improvement in new-metrics.rkt
Fix infer dotted cases when there are constraints on the dbound.

Closes PR 14593.
Add syntax property that tracks the exported name

This establishes a communication channel between the
contract system and TR. TR normally can't track the
relationship between the identifier bound to the transformer
that produces the lifted value expression (which has the
type in the environment) and the lifted expression
itself.

This change adds that information in a syntax property.
Add support for typechecking contracted functions
Add types and tests for racket/format
Add a test for the new kw app property propagation
Address some PR feedback
Fix copy-properties