ParmEst: Avoid ComponentUID in favor of Suffixes during model build

[djlaky]

Summary

Avoid using strings/component UID lookups in the modern parmest interface. @sscini

Rationale

The current interface still uses a ComponentUID lookup where we could be using the suffix to adjust things.

pyomo/pyomo/contrib/parmest/parmest.py

Lines 217 to 225 in 98d3076

	for name, val in thetavals.items():
	theta_cuid = ComponentUID(name)
	theta_object = theta_cuid.find_component_on(instance)
	if val is not None:
	# print("Fixing",vstr,"at",str(thetavals[vstr]))
	theta_object.fix(val)
	else:
	# print("Freeing",vstr)
	theta_object.unfix()

Description

Need to use suffix names instead. This code may become deprecated after using the new update_<> code has been added. #3650

Also relevant: #3575