ci: bats test reporting

[fmorency]

Generate and collect bats test reports for display in the CircleCI Tests tab.

This PR uses my fork of the bazel-bats rule until filmil/bazel-bats#22 is merged.

You can now see test results in the Tests tab.

We also have access to CircleCI Insight. See https://app.circleci.com/insights/github/liftedinit/many-rs/workflows/ci/tests?branch=pull/355

Resiliency test example in https://app.circleci.com/pipelines/github/liftedinit/many-rs/1487

Fixes #332

[codecov-commenter]

Codecov Report

Merging #355 (326e98f) into main (4984260) will decrease coverage by 0.07%.
The diff coverage is n/a.

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@@            Coverage Diff             @@
##             main     #355      +/-   ##
==========================================
- Coverage   82.95%   82.88%   -0.07%     
==========================================
  Files         130      130              
  Lines       15139    15138       -1     
==========================================
- Hits        12558    12547      -11     
- Misses       2581     2591      +10     

see 2 files with indirect coverage changes

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