Remove deprecated modules (asyncio, sockets, ftpclient) (#10401)

tests/async/tasyncawait.nim

@@ -1,7 +1,7 @@
 discard """
   output: "5000"
 """
-import asyncdispatch, nativesockets, net, strutils, os
+import asyncdispatch, asyncnet, nativesockets, net, strutils, os
 
 var msgCount = 0
 
@@ -12,20 +12,22 @@ const
 var clientCount = 0
 
 proc sendMessages(client: AsyncFD) {.async.} =
-  for i in 0 .. <messagesToSend:
+  for i in 0 ..< messagesToSend:
     await send(client, "Message " & $i & "\c\L")
 
 proc launchSwarm(port: Port) {.async.} =
-  for i in 0 .. <swarmSize:
-    var sock = newAsyncNativeSocket()
+  for i in 0 ..< swarmSize:
+    var sock = createAsyncNativeSocket()
 
     await connect(sock, "localhost", port)
     await sendMessages(sock)
     closeSocket(sock)
 
 proc readMessages(client: AsyncFD) {.async.} =
+  # wrapping the AsyncFd into a AsyncSocket object
+  var sockObj = newAsyncSocket(client)
   while true:
-    var line = await recvLine(client)
+    var line = await recvLine(sockObj)
     if line == "":
       closeSocket(client)
       clientCount.inc
@@ -37,7 +39,7 @@ proc readMessages(client: AsyncFD) {.async.} =
         doAssert false
 
 proc createServer(port: Port) {.async.} =
-  var server = newAsyncNativeSocket()
+  var server = createAsyncNativeSocket()
   block:
     var name: Sockaddr_in
     name.sin_family = toInt(AF_INET).uint16