feat: Make the rock toughness scalable with the fracture size and test anisotropic toughness

[frankfeifan]

This PR is to add and test features of rock toughness.

Scalable rock toughness

a new feature that makes the rock toughness scalable with the fracture size if the hydraulic fracture is very large. The underlying mechanism is that the cohesive region of rock fractures may scale up with the fracture size, thereby increasing the critical fracture energy and thus toughness. The specific formulation is

KIC = KIC_base*(1 + scalingFactor*sqrt(L)) where L is the distance to the fracture origin.

Here are the changes in this PR:

• Change rockToughness to baseRockToughness, and add toughnessScalingFactor and fractureOrigin in SurfaceGenerator. fractureOrigin is manually input now, but can be removed later if we can find the fracture origin from the initial fracture geometry.
• Plot K_IC by making it a field variable in fractureSubRegion,so that one can visualize the toughness in vtk.
• Add a simple test to demonstrate the feature

Relevant references: Scholz, 2010, McClure, 2023

Anisotropic toughness

Existing hydrofracture solver has the capability to assign anisotropic toughness, but looks like there is no relevant test. An example is added to test this feature. Also, some changes may be needed to make this feature easier to use for users.

• Add an example to test anisotropic rock toughness

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 39 lines in your changes missing coverage. Please review.

Project coverage is 56.57%. Comparing base (3b5b5a6) to head (af20655).

Files with missing lines	Patch %	Lines
...sicsSolvers/surfaceGeneration/SurfaceGenerator.cpp	0.00%	36 Missing ⚠️
...sicsSolvers/surfaceGeneration/SurfaceGenerator.hpp	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3310      +/-   ##
===========================================
- Coverage    56.59%   56.57%   -0.02%     
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  Files         1064     1064              
  Lines        89766    89797      +31     
===========================================
  Hits         50807    50807              
- Misses       38959    38990      +31     

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[CusiniM]

maybe initialRockToughness ?