alter lookupbykey return type to be optional

[roger-bosman-da]

In theory, damlc catches calls to lookupbykey with negative (yielding an error) or 0 (yielding the empty list []) n. That being said, to accomodate handwritten LF and to be a bit more precies, we wrap the lookupbykey in an optional, where None indicates failiure (such as a n < 1).

This PR implements the daml side of this change.

• Change "the staging version" (compiler always just knows of 1) to rc2
• Change the type of the builtin ULookupNByKey to include an Optional
• alter lookupNByKey to force the Optional, yielding an error if it is None (it should never be None when compiling with damlc, since n < 1 is already caught by the implementation of lookupNByKey
• move all lookup functions to Prelude and hide/reexport what needs to be in DA.ContractKeys (this way lookupByKey can use lookupNByKey and does not have to repeat the fromOption`)
• updated haddoc (fixes NUCK: add stdlib documentation for queryNByKey #22673)

Furthermore, since the change involves a change to the daml-lf json, the golden check was uncommented as well.

Canton companion PR: https://github.com/DACH-NY/canton/pull/32018
GHC companion PR: digital-asset/ghc#193

Steps taken:

1. [DONE] Daml ad-hoc release that sets type to optional
2. [DONE] Canton ad-hoc release with DamlScriptIT tests (the only one who use daml) disabled
3. [DONE] Daml ad-hoc release depending on canton ad-hoc of step 2
4. [DONE] Merge canton in main depending on daml ad-hoc of step 3
5. [IN PROGRESS] Merge sdk in main depending on canton snapshot of step 4

[roger-bosman-da]

/azp run

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