Edje_Entry: check selection before the cursor position change.

Edje_Entry: check selection before the cursor position change.

Summary:
change position of the main textblock cursor
in depends of the selection is present. Change cursor position to
the start or end of selection only when selection is present.
@fix

Test Plan:
Press "Up" and "Down" arrow keys on selected and normal text.
For selected text: the entry cursor should be placed one line
   above or below selection block (in depends from pressed button).
For normal text: the entry cursor should be placed one line
   above or below of the current cursor position.

Reviewers: tasn, Hermet, herdsman

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D2948