Cardano Updates

rather than partially addressed for a related context.

There's a view that these CPSs are specifically for mainnet and it
confuses matters to interpret these problem statements in the context of
Cardano chains other than mainnet.

* change artefact CPS discussion link to seminal PR

* added `Original PR` metadata label

Specify unValueData canonicality checks: require strictly ascending, distinct keys for both outer (currency symbols) and inner (token names) maps; fail on empty inner maps and zero-quantity entries; keep existing bounds/size constraints.

Add scaleValue builtin to the operation list: multiply all quantities by a provided integer, drop zeros / remove empty inner maps to preserve invariants, and fail on out-of-bounds results.

This allows `unValueData` to simultaneously serve two purposes, the first of which is to enforce that a `BuiltinData` is a canonical multi-asset value in data encoding, the second is to convert that `BuiltinData` to `BuiltinValue`. 

Importantly, this should allow the ex-unit cost of `unValueData` to be linear instead of quadratic.

Revert accidental upstream sync merge

This reverts commit 037e34258eaa84acbbfb1a91e3a01b2469d1c7a6, reversing
changes made to 665f397ef8fbfdd25390fb9c4cab0abe30feda25.

CIP-???? | On-Chain Surveys and Polls#1107

Signed-off-by: Chris Gianelloni <[email protected]>