Switch to using get_solver in BlockTriangularizationInitialization

[dallan-keylogic]

Previously, we had been using SolverFactory directly to get a solver to use in block triangularization because some of the default config options for IDAES caused solver failures. We should try to switch to using get_solver now that we've got better scaling and some bugs in Pyomo have been fixed. Also, we need to change the writer_config option in the block triangular solver from False to True.

Additionally, we may need calculate_variable_from_constraint to look for the constraint scaling factor when checking the convergence criteria.

Also, large_residuals_set presently returns a dict with Pyomo Constraints as keys (!) when using the return_residual_values=True option. That should be switched to a ComponentMap.

[ksbeattie]

@dallan-keylogic moving this to Feb release.