feat: add State constructor with Array of Subsets

[kyle-cochran]

Adds a constructor to the State class to directly build a custom State from an Array of Subsets.

This constructor will presumably cause a larger memory footprint, but is more straightforward to use than the Broker constructor.

This downfall should be mitigated in Python with the introduction of the CustomState meta-class stuff.

[codecov]

Codecov Report

Merging #238 (6edc53a) into main (9b7810a) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #238      +/-   ##
==========================================
+ Coverage   82.79%   82.81%   +0.01%     
==========================================
  Files          62       62              
  Lines        4744     4748       +4     
==========================================
+ Hits         3928     3932       +4     
  Misses        816      816              

Files	Coverage Δ
...penSpaceToolkit/Astrodynamics/Trajectory/State.cpp	100.00% <100.00%> (ø)

[phc1990]

LGTM, left minor comments.