[P4_Symbolic] Use table and action aliases as keys in the synthesized table entries to be compatible with PDPI. Move GetIrTable to symbolic/util.cc to increase code sharing. Implement AddConstraintsToForbidVrfZero to avoid synthesizing table entries with values of VRF 0. Add constraints for acl_pre_ingress_table to respect the entry restrictions. Add GetTableEntryPriorityType to obtain the priority type.

[P4_Symbolic] Use table and action aliases as keys in the synthesized table entries to be compatible with PDPI. Move GetIrTable to symbolic/util.cc to increase code sharing. Implement AddConstraintsToForbidVrfZero to avoid synthesizing table entries with values of VRF 0. Add constraints for acl_pre_ingress_table to respect the entry restrictions. Add GetTableEntryPriorityType to obtain the priority type. #4598