Add styleData.totalWidth for TabViewStyle::tab

[ChangeLog][QtQuickControls][Styles] Added styleData.totalWidth
property for TabViewStyle::tab component.

Task-number: QTBUG-37021
Change-Id: I76c29d132602926d9dacf690b09f556292359bf6
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
TableView: fix activeFocusOnTab behavior

Autotest is included.

Task-number: QTBUG-36950
Change-Id: I94c5b5225437ce87365740ea7423b09737dd275a
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Caroline Chao <caroline.chao@digia.com>