Fix Ijson metadata reader corner cases

[briancoutinho]

What does this PR do?

The fast ijson reader has some bugs/corner cases fixed here

1. Device info = [] , this can happen on CPU trace
2. nested arrays and maps inside the 2nd level metadata like "distributed Info". For now we are going to ignore this and support them in detail later.
3. Fix param import test

Testing: Added a cpu only trace and unittest for these corner cases. pytest tests/test_trace_parse.py -k test_ijson_metadata_reader

Before submitting

• [ ] Was this discussed/approved via a Github issue? (no need for typos, doc improvements)
  • [x] N/A
• [x] Did you write any new necessary tests?
  • [ ] N/A
• [ ] Did you make sure to update the docs?
  • [x] N/A
• [x] Did you update the changelog?
  • [ ] N/A

[facebook-github-bot]

@briancoutinho has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@briancoutinho has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[fengxizhou]

LGTM.

[facebook-github-bot]

@briancoutinho has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@briancoutinho merged this pull request in facebookresearch/HolisticTraceAnalysis@dcd33669d383f812e626ead8e2ebbe1a08f9bd73.