libtracker-data: Switched all GValueArray --> GArray

GValueArray is deprecated
libtracker-data, tracker-writeback: Switched all g_io_scheduler_push_job() --> g_task_run_in_thread()

g_io_scheduler_push_job() is deprecated
Fix GValue memory handling
tracker-writeback: Use cancellable for GTask from data
Merge branch 'fix-deprecations'