Inference CLI fixes

[talmo]

Fixes in the inference CLI entrypoint for some performance enhancements, tests and bug-fixes.

[codecov-io]

Codecov Report

Merging #459 (2ea560b) into develop (83201d6) will increase coverage by 0.68%.
The diff coverage is 91.66%.

@@             Coverage Diff             @@
##           develop     #459      +/-   ##
===========================================
+ Coverage    64.14%   64.82%   +0.68%     
===========================================
  Files          121      121              
  Lines        18253    18259       +6     
===========================================
+ Hits         11708    11837     +129     
+ Misses        6545     6422     -123     

Impacted Files	Coverage Δ
sleap/nn/data/confidence_maps.py	73.58% <ø> (+7.54%)	⬆️
sleap/nn/inference.py	65.01% <90.00%> (+4.50%)	⬆️
sleap/nn/data/pipelines.py	89.25% <100.00%> (+9.70%)	⬆️
sleap/nn/data/providers.py	67.39% <100.00%> (ø)
sleap/nn/training.py	62.91% <0.00%> (+3.85%)	⬆️
sleap/nn/heads.py	100.00% <0.00%> (+4.76%)	⬆️
sleap/nn/data/inference.py	55.38% <0.00%> (+5.64%)	⬆️
... and 1 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 292446e...2ea560b. Read the comment docs.