Fix onNetworkMessage event memory leak

[maattch]

Pull Request Prelude

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

Issues addressed:
Fix memory leak

How to test:
Disable Player:onNetworkMessage event and send packets with unknown opcode to server, such as from store.

[MillhioreBT]

In the best-case scenario, Lua will clean up the object; in the worst-case scenario, there will be a memory leak. That is correct—thank you for catching this issue.

However, I would prefer if you made some adjustments to the code.

1. Construct the unique_ptr directly in the lambda's scope by calling std::make_unique.
2. Make the msg parameter passed by reference in the methods: parsePlayerNetworkMessage and playerOnNetworkMessage.

Please do not forget to use CCLANG format, so we can merge it.

[MillhioreBT]

You are right, anyway you can not pass a mutable lambda to the addTask method, so its solution seems to be the only option for now, it only fixes the cclang format.

Although you can still pass by reference to the method tfs::events::player::onNetworkMessage, doing so saves a call to std::move.