[Edje] Update anchor and item tags when text is deleted by _edje_entry_imf_event_dele...

[Edje] Update anchor and item tags when text is deleted by _edje_entry_imf_event_delete_surrounding_cb.

Summary:
Anchor and item tags should be updated when text is changed.
In _edje_entry_imf_event_delete_surrounding_cb function,
the text is changed by "evas_textblock_cursor_range_delete" API
and there was no update about anchor and item tags.

It can result that the tags hang in the air after deleting.

Reviewers: tasn, woohyun, seoz, jihoon

Reviewed By: tasn

CC: cedric
Differential Revision: https://phab.enlightenment.org/D368