ENH: Simulation Save and Load in JSON Files

[phmbressan]

Pull request type

• Code changes (bugfix, features)

Checklist

• Tests for the changes have been added (if needed)
• Docs have been reviewed and added / updated
• Lint (black rocketpy/ tests/) has passed locally
• All tests (pytest tests -m slow --runslow) have passed locally
• CHANGELOG.md has been updated (if relevant)

New behavior

This PR improves rocketpy encoding and introduces decoding functionalities. The way this works is:

• If the is a to_dict or from_dict method, they are used to perform the (de)encoding;
• Otherwise, a default encoding of all vars() and constructor based decoding is done.

Breaking change

• Yes
• No

Additional information

PR #679 should be merged first.

Here are some of the steps that could be improved:

• Verify why the test for hybrid motor flight requires higher tolerances;
• Test if all of the atmospheric models of Environments can be decoded without requiring re-read of files or API;
• Evaluate whether we should encode outputs or only the minimum required information to decode the class from its init;
• (Optional) Expand implementation to AirBrakes + Controllers and new classes.

Some important remarks:

• The simple getting started simulation is essentially identical comparing the store & load, the only difference is the random lag and noise from Parachute class. I could not found a simple solution to reset those and always get the same results.

[codecov]

Codecov Report

Attention: Patch coverage is 82.79070% with 37 lines in your changes missing coverage. Please review.

Project coverage is 76.21%. Comparing base (c21e2d1) to head (022fa57).
Report is 11 commits behind head on develop.

Files with missing lines	Patch %	Lines
rocketpy/environment/environment.py	63.04%	17 Missing ⚠️
rocketpy/motors/tank_geometry.py	68.42%	6 Missing ⚠️
rocketpy/_encoders.py	90.90%	4 Missing ⚠️
rocketpy/motors/tank.py	89.47%	2 Missing ⚠️
rocketpy/rocket/parachute.py	88.23%	2 Missing ⚠️
rocketpy/simulation/flight.py	60.00%	2 Missing ⚠️
rocketpy/motors/motor.py	66.66%	1 Missing ⚠️
...cketpy/rocket/aero_surface/fins/elliptical_fins.py	66.66%	1 Missing ⚠️
rocketpy/rocket/components.py	50.00%	1 Missing ⚠️
rocketpy/rocket/rocket.py	95.23%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #695      +/-   ##
===========================================
+ Coverage    76.06%   76.21%   +0.14%     
===========================================
  Files           99       99              
  Lines        11278    11486     +208     
===========================================
+ Hits          8579     8754     +175     
- Misses        2699     2732      +33     

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[GabrielBarberini]

LGTM