This commit mainly fixes errors caused by deallocating resources in the garbage
collector thread. Using ecore_main_loop_thread_safe_call_async to queue
resource deallocation in the main thread seems to solve it.
Also, some efl_ref calls are added in places they were missing, mainly
objects that unref in the destructor thus taking ownership if efl_ref is not
Also fix improper resource deallocation in tests that were causing it to crash,
enabling it to call Efl.All.Shutdown again. This allocation and the deallocation
process was moved from the Eo class constructor to static class methods that are
called in the test 'set up' and 'tear down' methods.
Queuing resource deallocation in the main thread make it mandatory that tests
call Efl.App.AppMain.Iterate() if they want to check proper resource
deallocation (like TestFunctionPointers.set_callback_inherited_called_from_c).
Remove duplicated declaration of 'eflcustomexportsmono' in meson in order to fix
some linking problems.
Remove some unused code around deallocation functions that had to be reworked.
Object allocation is now supplied with the call site information it expects
(file name and line for _efl_add_start).
Depends on D8550