Finish (re)naming D2Net functions

[Lectem]

D2Net_10006
Should probably be SERVER_Send or SERVER_SendToClient. (if option n°2, then rename CLIENT_Send to CLIENT_SendToServer)

Here are names from @Necrolis we may want to get inspiration from

D2Net.#10000 - InitSystem
D2Net.#10001 - ShutdownSystem
D2Net.#10002 - Wait
D2Net.#10003 - CreateQServer
D2Net.#10004 - CloseQServer
D2Net.#10005 - SendToServer
D2Net.#10006 - SendToClient
D2Net.#10007 - RecvFromBufferClt
D2Net.#10008 - RecvFromHiPriorityBufferClt
D2Net.#10009 - <Missing?????> -> assuming this is RecvFromLoPriorityBufferClt
D2Net.#10010 - RecvFromBufferSrv
D2Net.#10011 - RecvFromHiPriorityBufferSrv
D2Net.#10012 - RecvFromLoPriorityBufferSrv
D2Net.#10013 - GetSocketName
D2Net.#10014 - GetIPAddress
D2Net.#10015 - CreateConnection
D2Net.#10016 - CloseConnection
D2Net.#10017 - Connect
D2Net.#10018 - SetQServerData(0xBD8)
D2Net.#10019 - SetConnectionCallback
D2Net.#10020 - SetConnectionData
D2Net.#10021 - GetConnectionData
D2Net.#10022 - Wait(0xBD4)
D2Net.#10023 - SetQServerMode
D2Net.#10024 - GetLastWSAError
D2Net.#10025 - CreatePollThread
D2Net.#10026 - SetMaxClients
D2Net.#10027 - GetMaxClients
D2Net.#10028 - Return
D2Net.#10029 - Return
D2Net.#10030 - GetClientPacketSize
D2Net.#10031 - GetServerPacketSize
D2Net.#10032 - CloseAllConnections
D2Net.#10033 - GetQServerIP
D2Net.#10034
D2Net.#10035
D2Net.#10036
D2Net.#10037
D2Net.#10038
D2Net.#10039 - GetSendFunction
D2Net.#10040 - GetDataFunction

Originally posted by @Lectem in #96 (comment)