elementary_test: Search menu performance optimization.

elementary_test: Search menu performance optimization.

Summary:
elementary_test search menu is created again and again
at each search query. Here the optimaization is to remember
the menu item and retain them instead of deletion and reuse them.

Signed-off-by: Umesh Tanwar <umesh.tanwar@samsung.com>
Test Plan:
search item in elementary_test and measure the
performace time.

Reviewers: jpeg

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D4218

Signed-off-by: Jean-Philippe Andre <jp.andre@samsung.com>