General lock order:
- Client execute lock
- Server state lock
- Server channel tree
- Client channel tree

When executing a command:
    Lock order:
    - Client execute lock
    - Client state lock
    - Server state lock (Server should not try to change state while a client is executing something)
    Notes:
    The server might be null or the default server.
    This must be checked via the given macro!

Disconnect/unregister a client:
- Lock client execute lock
- Lock server state
- Unregister client from server and set server variable to nullptr
- Underlying server (UDP, Web, etc. disconnect)

Client channel tree connect/mode/disconnect:
- Lock client execute lock
- Lock server channel tree in write mode
- Lock client channel tree in write mode
- Move client & notify (notify required all clients to have their channel tree locked in shared mode)

Command lock overview:
    CommandResult handleCommandClientUpdate(Command&);
    CommandResult handleCommandClientEdit(Command&);
    CommandResult handleCommandClientEdit(Command&, const std::shared_ptr<ConnectedClient>& /* target */);
    CommandResult handleCommandClientMove(Command&);
    CommandResult handleCommandClientGetVariables(Command&);
    CommandResult handleCommandClientKick(Command&);
    CommandResult handleCommandClientPoke(Command&);

    CommandResult handleCommandChannelSubscribe(Command&); read lock: server channel tree => client lock write
    CommandResult handleCommandChannelSubscribeAll(Command&); read lock: server channel tree => client lock write
    CommandResult handleCommandChannelUnsubscribe(Command&); read lock: server channel tree => client lock write
    CommandResult handleCommandChannelUnsubscribeAll(Command&); read lock: server channel tree => client lock write
    CommandResult handleCommandChannelCreate(Command&); write lock server channel tree => iterate clients lock (write)
    CommandResult handleCommandChannelDelete(Command&); write lock server channel tree => iterate clients lock (write)
    CommandResult handleCommandChannelEdit(Command&); write lock server channel tree
    CommandResult handleCommandChannelGetDescription(Command&); read lock: server channel tree
    CommandResult handleCommandChannelMove(Command&); write lock server channel tree

    CommandResult handleCommandChannelAddPerm(Command&); read lock: server channel tree => all clients write lock
    CommandResult handleCommandChannelDelPerm(Command&); read lock: server channel tree => all clients write lock

    CommandResult handleCommandChannelGroupDel(Command&); read lock: server channel tree => all clients in the group should not be allowed to switch a channel
    CommandResult handleCommandSetClientChannelGroup(Command&); read lock: server channel tree => client should not be allowed to switch channel

    CommandResult handleCommandPluginCmd(Command&);

    CommandResult handleCommandClientMute(Command&);
    CommandResult handleCommandClientUnmute(Command&);

    //Original from query but still reachable for all
    CommandResult handleCommandClientList(Command&);

    CommandResult handleCommandClientFind(Command&);
    CommandResult handleCommandClientInfo(Command&);

    CommandResult handleCommandVerifyChannelPassword(Command&); read lock: server channel tree

    handleCommandChannelFind read lock: server channel tree
    handleCommandChannelInfo read lock: server channel tree

    General command handling: client_command_lock
        Ensure that only one command at time will be handeled


    Read access server channel tree: read lock channel_tree_lock
    Write access server channel tree: lock channel_tree_lock
    Write access client channel tree: read lock channel_tree_lock => lock client channel tree
        if we write to the server channel tree no client should have their channel tree updated
    Read access client channel tree: no lock required
        Note: the server channel tree should not be accessed!

    Move client acts like access server channel tree: write lock channel_tree_lock => for each client write lock their tree


TODO: Some kind of perm channel lock
TODO: Fix handleCommandChannelEdit

Test: Channel hide & show with clients! Multiple clients as well!