Simplify location pointer names

After #155 (closed), we now get the something like the following for linearized models (example from !196 (comment 335492)):

  disc .S_gate1_closed.LPE_S_gate1_closed S_gate1_closed in any;
  disc .S_gate1_opened.LPE_S_gate1_opened S_gate1_opened in any;
  disc .S_gate2_closed.LPE_S_gate2_closed S_gate2_closed in any;
  disc .S_gate2_opened.LPE_S_gate2_opened S_gate2_opened in any;

The LPE_S_gate1_closed location pointer enumeration name contains the absolute name of the original automaton. This is not needed, as it is defined in that scope. We could for instance name it LP for location pointer, or LPE for location pointer enum, or LPV for location pointer values, or so.

This is a change for the ElimLocRefExprs CIF to CIF transformation. It also influences linearization.