Make SimpleExpression copy the received array before returning it

[TPGamesNL]

Description

The Javadoc of Expressions getArray and getAll state that the returned array must not be an internal array (i.e. it can be modified freely). However, the Javadoc of SimpleExpression#get(Event) and PropertyExpression#get(Event, F[]) do not have this requirement.

The implementations of SimpleExpression getArray and getAll, and PropertyExpression#getAll did not use this properly, as it assumed the returned arrays (from the get methods) were not internal, as they were sometimes directly returned. This means that an internal array could be returned in a getArray or getAll method, which should not be allowed.

I changed it so the implementations of getArray and getAll will now never return the array received directly. Alternatively, I could've added the requirement to SimpleExpression and PropertyExpression to not return an internal array. However, since these classes are made to allow for an simpler implementation of expressions, I felt like this is not something those simple implementation should be expected to deal with (and on top of that, it'd be a breaking change).

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Target Minecraft Versions: any
Requirements: none
Related Issues: #5322

[TheLimeGlass]

Wont this affect how the changers work? The change method uses the getArray and would allow for modification of the internal objects using super.change if that's the goal of the expression.

[TPGamesNL]

Wont this affect how the changers work? The change method uses the getArray and would allow for modification of the internal objects using super.change if that's the goal of the expression.

No, changers operate on the objects in the array, not on the array itself. The objects can still be modified just fine. Besides, usually getArray already makes a copy of the array it got from get, this was just one case that wasn't covered.