feat: adjust ParsingNeuralNetwork to build model directly from the model slug

[jkbmrz]

Adding an update to ParsingNeuralNetwork build() method to match the recent changes in DAI (v3alpha6) that allow models to be built directly from slug:

• Previous functionality: pipeline.create(ParsingNeuralNetwork).build(<CameraNode>, <dai.NNModelDescription OR dai.NNArchive>)
• The updated functionality: pipeline.create(ParsingNeuralNetwork).build(<CameraNode>, <Slug>)

Additionally, examples script was adjusted to reflect the new changes. Moreover, slug variables were renamed to models (new naming convention)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 22.22222% with 7 lines in your changes missing coverage. Please review.

Project coverage is 32.84%. Comparing base (37a2d92) to head (c9bee4f).
Report is 10 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
depthai_nodes/parsing_neural_network.py	22.22%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #134      +/-   ##
==========================================
- Coverage   33.40%   32.84%   -0.56%     
==========================================
  Files          68       68              
  Lines        3739     3717      -22     
==========================================
- Hits         1249     1221      -28     
- Misses       2490     2496       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[aljazkonec1]

Looks good, just one comment about keeping up with depthai definitions

[klemen1999]

LGTM