Implement reverse for AbstractParametricCurve and other changes

[DanielVandH]

• Implement reverse(::AbstractParametricCurve)
• Fix LineSegment should return the endpoints at t=0/t=1 #194
• Restructured the curve files so that each curve has its own file.
• Fixed an issue with over-enrichment, sometimes leading to duplicate points, for LineSegment curves.
• Fixed an issue with orientation markers sometimes being nearly identical by using uniquetol as intended.
• For N > 32, replaced the recursive tuple handling functions with a direct, non-stable, method.

[codecov]

Codecov Report

Attention: Patch coverage is 98.88984% with 13 lines in your changes missing coverage. Please review.

Project coverage is 94.94%. Comparing base (91dfbe7) to head (79afd2f).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...data_structures/mesh_refinement/curves/abstract.jl	98.91%	4 Missing ⚠️
...ta_structures/mesh_refinement/boundary_enricher.jl	50.00%	3 Missing ⚠️
...structures/mesh_refinement/curves/ellipticalarc.jl	97.24%	3 Missing ⚠️
...ructures/mesh_refinement/curves/piecewiselinear.jl	94.87%	2 Missing ⚠️
.../data_structures/mesh_refinement/curves/bspline.jl	99.23%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #195      +/-   ##
==========================================
- Coverage   95.01%   94.94%   -0.07%     
==========================================
  Files          95      101       +6     
  Lines       10147    10178      +31     
==========================================
+ Hits         9641     9664      +23     
- Misses        506      514       +8     

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