fix crash and leak in action:register and moveevent:register

[yamaken93]

Pull Request Prelude

• [x] I have followed proper The Forgotten Server code styling.
• [x] I have read and understood the contribution guidelines before making this PR.
• [x] I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

Better registerLuaEvent code, allow to register the same action/moveevent to aid, uid, item id and position. No use after delete anymore in action:register and moveevent:register. No memory leak/waste of memory since we borrow/steal the vector from the original event making the future copies copy empty vector.

Issues addressed: #3692

[MillhioreBT]

~I think the compiler knows if this should be returned with or without movement samantic, but since I can't confirm it, I think it would be best to do that @ranisalt suggested.~

Definitely, Ranisalt's suggestion is the correct option for this case. Although moving the vectors means they no longer belong to the object, the object will maintain valid but undefined vectors. I don't think anyone would want to use these undefined vectors, but it's better to maintain correct logic throughout the code.

[Codinablack]

I'm unsure about this. If I recall correctly, using a variable after moving it is undefined behavior.

It would probably be better to create a new one on the stack, swap with the one on the current object, and return the one on the stack (it will elide the copy/move):

std::vector newVector{};
std::swap([this->]oldVector, newVector);
return newVector;

So basically something like this is needed to fix this PR

std::vector<uint32_t> borrowItemIdRange() {
    std::vector<uint32_t> temp;
    temp.swap(itemIdRange);
    return temp;
}

Right? If all the new "borrowed" methods looked like this, or along these lines (obviously variable names would change), then the PR would be solid?