[P4_Symbolic] Move symbolic/concrete context to context.{cc,h} separated from symbolic.{cc,h}, and make the context-related objects constructed along with the solver state and then passed along the symbolic evaluation.

[P4_Symbolic] Move symbolic/concrete context to context.{cc,h} separated from symbolic.{cc,h}, and make the context-related objects constructed along with the solver state and then passed along the symbolic evaluation. #4364