Move away from AsyncHitTest messages to handle tap

Move away from AsyncHitTest messages to handle tap

We have an existing mechanism to post-handle tap events.
This mechanism lives in render_view_observer_efl.cc
and is used by the renderer to inform the browser to
play sound in response to clicking a link.
In order to have the context information, an extra hit
test is performed on the renderer side, and browser gets
notified by a message.

In order to eliminate the last client of the hit test
ping-pong messaging in the text selection code, patch
extends the mechanism described above to provided the
information needed by text selection (read is_content_editable),
in addition to the current link information.

Original beta/m42 patch:
- http://165.213.202.130/gerrit/#/c/86093/ , reviewed by
Janusz Majnert, Arnaud Renevier.

Bug: http://107.108.218.239/bugzilla/show_bug.cgi?id=6663

Reviewed by: Janusz Majnert

Change-Id: I0b5d7f0b0d457bd89e911a2768ce0c480f331f9b
Signed-off-by: Antonio Gomes <a1.gomes@samsung.com>