tc: Reorganize test cases based on libtpl-egl APIs

tc: Reorganize test cases based on libtpl-egl APIs

Reorganize test cases based on the name of libtpl-egl APIs to cover
all flows of libtpl-egl APIs. Followings are changed in this patch:

 - Test cases are organized and renamed with DEFAULT and EXTRA cases.

 - Most of test cases are renamed with the function name of libtpl-egl APIs,
   and test name will represent its working flow.

example>

   TEST CASE                  |  TEST
   ------------------------------------------
   DEFAULT_tpl_display_get    |  success
   DEFAULT_tpl_display_get    |  failure_null

Change-Id: I86f6e16c75ceeba29b46356ab7d296b281acb934
Signed-off-by: Hoyub Lee <hoyub.lee@samsung.com>