Optimal non-builtin valueOf in plutus-ledger-api Data.Value (#7797)
Rewrites `PlutusLedgerApi.V1.Data.Value.valueOf` so the non-builtin lookup path walks the underlying `BuiltinList` directly via `unsafeDataAsMap` / `unsafeDataAsB` / `unsafeDataAsI`, compares keys with `equalsByteString`, and short-circuits on the first match. No `Maybe` is materialised: the "absent" answer is `0`, returned in-place by the `nilCase` of each traversal. Avoids `withCurrencySymbol`'s continuation + `Map.lookup`'s `Maybe`-wrapping, and bypasses the `ToData k`/`UnsafeFromData a` dictionary work that `AssocMap.lookup` does per element. Semantics preserved. Adds `Spec.Data.Value.test_valueOf`: a QuickCheck property that compiles `valueOf` via TH, evaluates it on the CEK machine, and compares the result against the host-Haskell `valueOf` for the same inputs. Differential test against the Plinth compiler — any divergence is a compilation bug, not a semantics bug. Budget evidence (lookup matrix, `unsafeDataAsValue` baseline) lives on the companion experimental branch `yura/issue-2242-valueof-evidence`, kept out of this PR to avoid carrying ~96 golden files that would only ever regenerate on upstream plugin/cost-model changes. For IntersectMBO/plutus-private#2242.