Add missing ITs for JSON Cadence parser

[lealobanov]

Description

• Add integration tests for untested classes in JSON Cadence serializer/deserializer

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For contributor use:

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the standards mentioned here.
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[github-actions]

Unit Test Results

  51 files  ±0    51 suites  ±0   7s ⏱️ ±0s
275 tests ±0  275 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 4075fe5. ± Comparison against base commit 4075fe5.

♻️ This comment has been updated with latest results.

[github-actions]

Integration Test Results

  7 files  ±0    7 suites  ±0   30s ⏱️ ±0s
33 tests ±0  33 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 4075fe5. ± Comparison against base commit 4075fe5.

♻️ This comment has been updated with latest results.

[franklywatson]

The tests ran locally but seems to fail in the CI here. I approved in the meanwhile.

[lealobanov]

@franklywatson yes, I noticed that the tests running against the network tend to throw "max rate exceeded" after running through the CI pipeline 2-3 times. I noticed the rate limit usually resets after 12-24 hours and then they are able to run again normally (just retriggered on this branch and they ran successfully)... not sure if we could do anything on our side to remove the request limit (could it be tied to the IP address of the Github VM used to run the tests?)