elm_win: remove elm_win_conformant_set/get from eo

elm_win: remove elm_win_conformant_set/get from eo

conformant set api give information to enlighten ment, this window
need to know the change of conformant size.
but in the future, window have to section background and forground.
if user set layout as content of background part, the layout size is
not changed by clipborad or keybord.

if user set layout as content of forground part of window, the layout size
is changed by clipboard or keyboard state.
and the window notify to the enlightenment it has interest soft input's state
automatically, without users api call