EditMenu iOS: show edit menu upon pressnhold on empty input field

If you press and hold on an input field that doesn't have focus, we
select the word under the cursor, which will make the menu show.
But if the field is empty, no word can be selected, so therefore no
menu will show.
This patch will check for this special case, and show the menu if
you pressnhold on an empty input field.

Change-Id: I7d2c137765471cb1ff1dc4f7e34577e5e1317dc0
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>
EditMenu iOS: don't show menu item 'select' when input field is empty

Make sure that we don't show the 'select' menu item if there is no
word that can be selected.

Change-Id: I24aec2f3b77a1bcdd1e71b5b2a853992476eb936
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>