Add ClientConnected() hook

[bionext03]

Add ClientConnected hook. Called after processing a client connection request.

[Giferns]

@bionext03 we have problem with this hook, that I didn't notice at the first test. When server starts from offline, log on my connect is

L 10/08/2021 - 04:12:09: [AIB DEBUG] RH_ClientConnected_Post(): (taskid: 39711)
L 10/08/2021 - 04:12:09: [AIB DEBUG] client_connect(): 85.249.45.145 (warned? taskid not found!)

but when i reconnect i get

L 10/08/2021 - 04:12:24: [AIB DEBUG] RH_ClientConnected_Post(): 85.249.45.145 (taskid: 64257)
L 10/08/2021 - 04:12:24: [AIB DEBUG] client_connect(): 85.249.45.145 (taskid: 64257, elapsed 0.066801)

In other words, IP provided by get_user_ip() in this hook will give us previous connection IP, not current. Sorry that i didn’t notice this at first test, I tested your version by reconnecting to the server, and I just didn’t notice the problem.

To get IP from this hook we need something like #221
Implementing it just for our purpose is a weird idea... Now i think bug need to be closed through ReAuthCheck, as intended to be.

[bionext03]

AMXX updates the client's ip address in the ClientConnect_Post metamod hook. We just need to add IRehldsServerData::GetNetFrom() to this hook to get the ip of the current client.