Support new DLC multi-animal configs

[roomrys]

Description

Support new DLC multi-animal config format.

Types of changes

• Bugfix
• New feature
• Refactor / Code style update (no logical changes)
• Build / CI changes
• Documentation Update
• Other (explain)

Does this address any currently open issues?

• Bodypart error when importing multi-animal DLC project #1162

Outside contributors checklist

• Review the guidelines for contributing to this repository
• Read and sign the CLA and add yourself to the authors list
• Make sure you are making a pull request against the develop branch (not main). Also you should start your branch off develop
• Add tests that prove your fix is effective or that your feature works
• Add necessary documentation (if appropriate)

Thank you for contributing to SLEAP!

❤️

[codecov]

Codecov Report

Merging #1204 (fdf600e) into develop (788179d) will increase coverage by 0.17%.
The diff coverage is 96.47%.

@@             Coverage Diff             @@
##           develop    #1204      +/-   ##
===========================================
+ Coverage    72.00%   72.18%   +0.17%     
===========================================
  Files          132      132              
  Lines        23328    23403      +75     
===========================================
+ Hits         16798    16893      +95     
+ Misses        6530     6510      -20     

Impacted Files	Coverage Δ
sleap/gui/app.py	78.53% <ø> (+0.07%)	⬆️
sleap/io/format/deeplabcut.py	84.86% <66.66%> (+14.86%)	⬆️
sleap/nn/inference.py	81.54% <97.12%> (+0.94%)	⬆️
sleap/gui/learning/dialog.py	63.65% <0.00%> (-0.48%)	⬇️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more