[Mesh][Solvers] Switch to using tensor product form to interpolate to plotting nodes for Quads and Hexes

[noelchalmers]

Switches the plotInterp operator to be the 1D interpolation operator in Quads and Hexes. This helps reduce setup time for very high order meshes, and reduces interpolation time when plotting.

[codecov]

Codecov Report

Merging #61 (d8fb731) into master (2a92cad) will decrease coverage by 0.49%.
The diff coverage is 62.56%.

@@            Coverage Diff             @@
##           master      #61      +/-   ##
==========================================
- Coverage   84.76%   84.27%   -0.50%     
==========================================
  Files         251      257       +6     
  Lines       19932    20080     +148     
==========================================
+ Hits        16896    16923      +27     
- Misses       3036     3157     +121     

Impacted Files	Coverage Δ
include/mesh.hpp	100.00% <ø> (ø)
include/mesh/mesh2D.hpp	0.00% <ø> (ø)
include/mesh/mesh3D.hpp	0.00% <ø> (ø)
libs/mesh/meshPlotInterpHex3D.cpp	0.00% <0.00%> (ø)
libs/mesh/meshPlotInterpQuad2D.cpp	0.00% <0.00%> (ø)
libs/mesh/meshPlotInterpQuad3D.cpp	0.00% <0.00%> (ø)
libs/mesh/meshPlotInterpTet3D.cpp	0.00% <0.00%> (ø)
libs/mesh/meshPlotInterpTri3D.cpp	0.00% <0.00%> (ø)
solvers/elliptic/src/ellipticPlotFields.cpp	0.00% <0.00%> (ø)
solvers/ins/src/insPlotFields.cpp	88.54% <77.77%> (+4.33%)	⬆️
... and 19 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2a92cad...a7279a8. Read the comment docs.