(De-)serialize BigInt from/to JSON number in Quint import

[thpani]

#2654 fixed the deserialization of QuintInt.value into a Scala BigInt.
However, this is not the only TypeScript bigint needing conversion:
All Quint IDs, plus the lookup table references, are also TypeScript bigints and should be deserialized into Scala BigInts.

upickle's built-in BigInt (de)serializer reads/writes BigInts only from/to JSON strings.
Thus, there's two options for Apalache <-> Quint compatiblity:

1. Read/write all bigints as strings from Quint.
2. Extend upickle to support (de)serializing BigInts from/to JSON numbers, which can be arbitrarily long. This is how json-bigint already behaves on the Quint side.

A brief investigation showed that approach (1) is non-trivial; for example, it would break the JSON re-import inside Quint.

This PR implements approach (2):

• Extend QuintDeserializer with custom BigInt{Reader,Writer} implicits to read/write JSON numbers.
• Port the remaining Quint IDs to BigInts.
• Revert commit 2a073ab, which wrapped all QuintInt.values in integration tests into strings as part of Deserialize QuintInt.value as BigInt #2654. Since we now read/write JSON numbers, this has become unnecessary.

Closes informalsystems/quint#1055

• Tests added for any new code
• Ran make fmt-fix (or had formatting run automatically on all files edited)
• Documentation added for any new functionality
• Entries added to ./unreleased/ for any new functionality

[Kukovec]

I assume the two json files are generated by something, so I didn't read them. The rest looks good.

[thpani]

I assume the two json files are generated by something, so I didn't read them. The rest looks good.

Aaah yes, that's the revert commit. Thanks!

[codecov-commenter]

Codecov Report

Merging #2661 (9f08cea) into main (8ce5374) will decrease coverage by 0.05%.
The diff coverage is 50.00%.

❗ Current head 9f08cea differs from pull request most recent head ece1090. Consider uploading reports for the commit ece1090 to get more accurate results

@@            Coverage Diff             @@
##             main    #2661      +/-   ##
==========================================
- Coverage   78.55%   78.50%   -0.05%     
==========================================
  Files         455      455              
  Lines       15795    15817      +22     
  Branches     2589     2570      -19     
==========================================
+ Hits        12407    12417      +10     
- Misses       3388     3400      +12     

Impacted Files	Coverage Δ
...ain/scala/at/forsyte/apalache/io/quint/Quint.scala	85.22% <ø> (ø)
...n/scala/at/forsyte/apalache/io/quint/QuintIR.scala	72.50% <50.00%> (-8.54%)	⬇️

... and 3 files with indirect coverage changes

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[shonfeder]

Awesome work! Glad to have the root cause sorted out :)