SimdJson upgrade

[mnorfolk03]

Updated simdjson to the latest version.

Now fields are identified as json ("x.y") rather than the previous slash method ("x/y"), thus the tests have been updated to accommodate this.

Additionally, added a GitHub workflow to run the tests.

[mnorfolk03]

@microsoft-github-policy-service agree

[dongx-psu]

I will do a code review in a week.

Dong

[dongx-psu]

Did a quick pass on the code. LGTM.

@mnorfolk03 Can you run some basic performance regression tests for at least one dataset? For example, run an experiment on a large enough Github dataset and see how it compares with the old version. When it is done, please plot the figure and put it here for reference.

@badrishc Could you please glance over the code as well? Also, we are switching the CI/CD to Github Actions for better integration.

[mnorfolk03]

Here is the data requested. This version will perform a bit worse when batchsize = 1, but it makes sense to switch to simdjson::ondemand, because it will perform better with larger batch sizes. Also note, that simdjson::dom, will perform worse than the ondemand.

[dongx-psu]

I think the code looks fine. @badrishc Can you check if it looks good to you? If so, I will merge it back to master.