Implement interface boundaries

[DavidAKopriva]

Nascent code is now implemented to mesh interior regions to allow for multiple material applications.

[codecov[bot]]

Codecov Report

Merging #53 (6aa4753) into main (ae2f145) will increase coverage by 5.97%. The diff coverage is 90.90%.

@@            Coverage Diff             @@
##             main      #53      +/-   ##
==========================================
+ Coverage   68.00%   73.97%   +5.97%     
==========================================
  Files          68       68              
  Lines       10275    10259      -16     
==========================================
+ Hits         6987     7589     +602     
+ Misses       3288     2670     -618     

Flag	Coverage Δ
unittests	73.97% <90.90%> (+5.97%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
Source/3DSource/HexMeshObjects.f90	96.29% <ø> (ø)
...rves/DiscreteCurves/ChainedSegmentedCurveClass.f90	54.31% <ø> (ø)
Source/Foundation/Geometry.f90	82.92% <ø> (ø)
Source/HOHQMeshMain.f90	44.61% <0.00%> (-2.93%)	:arrow_down:
Source/Project/MeshProject.f90	75.59% <50.00%> (+4.01%)	:arrow_up:
Source/3DSource/Mesh3DOutputMethods.f90	98.07% <60.00%> (-0.95%)	:arrow_down:
Source/Mesh/MeshCleaner.f90	82.76% <82.00%> (+15.05%)	:arrow_up:
Source/MeshObjects/SMMeshObjects.f90	66.83% <83.33%> (+4.83%)	:arrow_up:
Source/3DSource/SimpleSweep.f90	90.32% <100.00%> (ø)
Source/HOHQMesh.f90	65.57% <100.00%> (ø)
... and 10 more

... and 4 files with indirect coverage changes

[DavidAKopriva]

The documentation still needs to be updated before a merge.

[andrewwinters5000]

New figure for the docs.