Ensure that unload event is called before unloading of functions regardless of order in script.

[TFSMads]

Problem

functions appearing before on unload event is unloaded before event is called.

Solution

When unloading a script unload event is moved to front of list so that it is triggered before unloading of functions.

Testing Completed

I have tested it on version 1.21.10.

Supporting Information

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Completes: #8233
Related: none

[APickledWalrus]

Rather than hardcoding this comparator in, I think an alternative option would be to unload based on Structure priority (in reverse order to loading)

[APickledWalrus]

I believe this won't work if the function is in a different script from the unload event structure. This needs to be reworked so that all structures across all unloading scripts are sorted together (similar to how it is done in the loading phase).

[TFSMads]

All structures across multiple scripts should now be unloaded in reverse order based on priority,

Testing completed

unloada.sk

function a():
	add 1 to {test-unload}

on unload:
	clear {test-unload}
	a()
	b()
	c()
	d()
	if {test-unload} is 4:
		broadcast "test-unload is 4"
	else:
		broadcast "test-unload is not 4 as expected"
	
function b():
	add 1 to {test-unload}

unloadb.sk

function c():
	add 1 to {test-unload}

on unload:
	clear {test-unload}
	a()
	b()
	c()
	d()
	if {test-unload} is 4:
		broadcast "test-unload is 4"
	else:
		broadcast "test-unload is not 4 as expected"
	
function d():
	add 1 to {test-unload}

All functions from both scripts are available in unload event.

[APickledWalrus]

I think this is almost ready, great work!