Internal
Validate and normalize P2PK/HTLC output options.
Normalizes and deduplicates pubkeys, then enforces that requested signature thresholds are satisfiable by the resulting key sets.
External callers use P2PKBuilder: P2PKBuilder.fromOptions(opts).toOptions()
P2PKBuilder.fromOptions(opts).toOptions()
Validate and normalize P2PK/HTLC output options.