feat: bind Solid definitions to Hex8 runtime elements

tests/CMakeLists.txt

@@ -34,6 +34,7 @@ add_executable(
     unit/core/source_identity_test.cpp
     unit/core/status_test.cpp
     unit/elements/element_factory_test.cpp
+    unit/elements/hex8_element_test.cpp
     unit/elements/euler_beam_3d_test.cpp
     unit/elements/finite_rotation_test.cpp
     unit/elements/mitc4_shell_test.cpp
@@ -50,6 +51,7 @@ add_executable(
     unit/math/vector_test.cpp
     unit/io/abaqus/domain_mapping_components_test.cpp
     unit/io/abaqus/domain_mapper_test.cpp
+    unit/io/abaqus/hex8_semantics_test.cpp
     unit/io/abaqus/eigen_domain_test.cpp
     unit/io/abaqus/hht_dynamic_domain_test.cpp
     unit/io/abaqus/thermal_domain_test.cpp