Coarsen and Fix Shape Mesh Adpat Improvements

[Angelyr]

Adds Improvements to Coarsen and Fix Shape Mesh Adaptation

• Documentation detailing the algorithms used in mesh adapt
• Coarsen is improved by modifying the algorithm to ensure that all short edges are collapsed to ensure a good quality
• Collapse runtime is improved by removing unnecessary findEntity calls and calculating invalid elements before collapse.
• Runtime of measuring tetrahedron quality is improved by reducing the number of object allocations and caching values that don't require recalculation.
• Fix shape is improved by adding new operators face swap and vertex reposition, in addition to changing the order that the operators are evaluated in.
• Snapping is modified to remove unnecessary float comparisons