fix wrong behaviour of SelectNone()

fix wrong behaviour of SelectNone()

1. It is wrong behaviour for the cursor position to be 0 when selection is canceled.
Keeping the previous cursor position is the proper behavior.

2. SelectNone() only works if selection is enabled.
In this case, if selection is canceled, EDITING state is more appropriate than INACTIVE.
In INACTIVE, it is difficult to continue editing work, such as the cursor being deactivated.

Change-Id: I0f5f678b3ea205bc334ca9d5cd6e7626f37d8d87
Signed-off-by: Bowon Ryu <bowon.ryu@samsung.com>