[M120 Migration] Support signal "tooltip,text,unset", "tooltip,text,set"
When mouse move over some HTML element,
we will notify WebBrowser about the tooltip information.
When mouse move over HTML element,
we will get related information form EventHandle.
Extract the tooltip string. Send tooltip set
notification when tooltip is not empty.
Otherwise, send tooltip unset notification.
Reference:
https://review.tizen.org/gerrit/#/c/291995
Change-Id: I8d40ce93583036a05238b85d483dcc2d3fe045c9
Signed-off-by: fangfengrong <fr.fang@samsung.com>