ecore: Add code for new API function 'ecore_main_loop_nested_get'

Summary: This commit adds the actual code to the function, which
returns the 'in_main_loop' variable so that we can detect if the
ecore_main_loop is actually running.

NB: Will be needed for new eldbus API function (yet to add).

@feature

Signed-off-by: Chris Michael <cp.michael@samsung.com>

src/lib/ecore/ecore_main.c

@@ -1006,6 +1006,12 @@ ecore_main_loop_quit(void)
 #endif
 }
 
+EAPI int 
+ecore_main_loop_nested_get(void)
+{
+   return in_main_loop;
+}
+
 EAPI Eina_Bool
 ecore_main_loop_animator_ticked_get(void)
 {