This moves the implementation of most methods from absl::Status to absl::status_internal::StatusRep, and ensures that no calls to absl::Status methods are in a cc file.

Stub implementations checking only inlined rep properties and calling no-op (RepToPointer) or out of line methods exist in status.h

PiperOrigin-RevId: 566187430
Change-Id: I356ec29c0970ffe82eac2a5d98850e647fcd5ea5