Named ordered dynamic properties lose their order in the editor property sheet

[TiberiumFusion]

When a part defines an ordered list of dynamic properties, if any of those properties have a key that collides with pac's list of known pac properties (like Name, Hide, Size, Scale, Stretch, etc), that property loses its intended ordering in the property sheet.

For example, if a part's GetDynamicProperties() returns a table like so:

{
  [1] = { key = "Shrink", ..., udata = { group = "extras", ... } },
  [2] = { key = "Stretch", ..., udata = { group = "extras", ... } },
}

...then one would expect the "extras" group in the property sheet to display item Shrink first, then item Stretch.
Instead, what happens is that Stretch appears first, then Shrink.

This is due to the following code:

pac3/lua/pac3/core/client/base_part.lua

Line 1033 in e40dfa5

function PART:GetProperties()

<snip>

pac3/lua/pac3/core/client/base_part.lua

Lines 1092 to 1104 in e40dfa5

	for _, variables in pairs(pac.VariableOrder) do
	for _, key in ipairs(variables) do
	for _, prop in ipairs(out) do
	if key == prop.key then
	if not done[key] then
	table_insert(sorted, prop)
	done[key] = true
	break
	end
	end
	end
	end
	end

...which forcibly re-sorts all properties (including dynamic properties in dynamic groups) by moving all properties that bear a known built-in pac property name to the top of the list. So, since Stretch is a built-in pac property on the trail part, the dynamic property with key Stretch gets moved to the top of the list. It happens on every single part too, e.g. if the faceposer part's GetDynamicProperties() returns the example table from above, that tables' ordering still gets clobbered and Stretch still gets moved to the top of the list, because PART:GetProperties() is applying sorting on built-in pac properties names for every single pac part to every single part, not just e.g. the faceposer part's known built-in names to the faceposer part. Regardless of whatever the original intent of this sorting was, its implemented is deeply flawed.