Implement private HHT field convergence policy and oracle tests

src/fesa/CMakeLists.txt

@@ -9,6 +9,7 @@ add_library(
     analysis/hht_dynamic_algebra.cpp
     analysis/hht_development_probe.h
     analysis/hht_dynamic_assembly.cpp
+    analysis/hht_field_convergence.cpp
     analysis/hht_reduced_operators.cpp
     analysis/hht_reduced_procedure.cpp
     analysis/hht_dynamic_procedure.cpp