Introduce E_Aux_Hint_Surface

Introduce E_Aux_Hint_Surface

This patch separates the responsibility of managing auxiliary hints out
from E_Comp_Wl_Client_Data to E_Aux_Hint_Surface.
The E_Aux_Hint_Surface is now responsible for managing auxiliary hints
for an E_Surface.

This separation of responsibility is aimed at decoupling these
functionalities from E_Comp_Wl_Client_Data, which currently handles many
mixed responsibilities.

Change-Id: Ibe991fa0fbb2ad704224290506c3b3368b84a21d