Newtonian Simulator Fixes and Cleanup

[Eric-Vin]

Description

This PR fixes several issues with the Newtonian simulator:

• Previously scaling was done per dimension, warping the objects.
• Objects were being drawn to a position that did not account for their rotation, leading to incorrect images and wobbling.
• Car dimensions are no longer hard-coded and are now drawn from the object's width and height on a per-object basis.
• Added a debug global parameter debugRender that always draws polygons to help verify that cars (or any future objects) are being drawn correctly.
• General code cleanup, removing several unused lines.

Issue Link

This will resolve Issue #304.

Checklist

• I have tested the changes locally via pytest and/or other means
• I have added or updated relevant documentation
• I have autoformatted the code with black and isort
• I have added test cases (if applicable)

Additional Notes

To verify that this resolves Issue #304, run an example Scenic program with the debugRenderer parameter set to True. An example is included below:
scenic examples/driving/badlyParkedCarPullingIn.scenic --2d --simulate --model scenic.simulators.newtonian.driving_model --time 200 --count 1 -p debugRender True

I've also included several screenshots showing the correct behavior which is now present:

[codecov]

Codecov Report

Attention: Patch coverage is 96.87500% with 1 line in your changes missing coverage. Please review.

Project coverage is 91.37%. Comparing base (0abbbcd) to head (77c9605).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/scenic/simulators/newtonian/simulator.py	96.87%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #309      +/-   ##
==========================================
- Coverage   91.37%   91.37%   -0.01%     
==========================================
  Files          54       54              
  Lines       13544    13555      +11     
==========================================
+ Hits        12376    12386      +10     
- Misses       1168     1169       +1     

Files with missing lines	Coverage Δ
src/scenic/simulators/newtonian/simulator.py	90.00% <96.87%> (+0.05%)	⬆️

... and 2 files with indirect coverage changes

[dfremont]

Looks great, just one tiny fix and a question.