Executable decimal inspection

Provides stored-bit and datum sign operations; the ten-way classification and all classification predicates; stored-word canonicality; all 22 IEEE comparison predicates; total ordering, magnitude ordering and sameQuantum.

Datum.quantumExponent is an additional finite-only query. Non-computational queries and sign operations do not signal exceptions. Quiet/signaling comparisons return their invalid flag explicitly. Import Inspection.Basic for proofs.