PS: Add more models and accept test changes.

Author: MathiasVP

powershell/ql/lib/semmle/code/powershell/frameworks/System.Net.model.yml

@@ -6,4 +6,13 @@ extensions:
       - ["system.net.sockets.tcpclient", "Method[getstream].ReturnValue", "remote"]
       - ["system.net.sockets.udpclient", "Method[endreceive].ReturnValue", "remote"]
       - ["system.net.sockets.udpclient", "Method[receive].ReturnValue", "remote"]
-      - ["system.net.sockets.udpclient", "Method[receiveasync].ReturnValue", "remote"]
+      - ["system.net.sockets.udpclient", "Method[receiveasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloaddata].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloaddataasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloaddatataskasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadfile].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadfileasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadfiletaskasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadstring].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadstringasync].ReturnValue", "remote"]
+      - ["system.net.webclient", "Method[downloadstringtaskasync].ReturnValue", "remote"]

powershell/ql/test/library-tests/frameworks/system_net_sockets/test.expected

@@ -1 +1 @@
-| test.ps1:1:1:18:0 | [synth] pipeline | Unexpected result: type="command line argument" |
+| test.ps1:1:1:20:93 | [synth] pipeline | Unexpected result: type="command line argument" |

powershell/ql/test/library-tests/frameworks/system_net_sockets/test.ps1

@@ -17,4 +17,4 @@ $data2 = $udpClient.Receive([ref]$remoteEndpoint2) # $ type="remote flow source"
 $receiveTask = $udpClient.ReceiveAsync() # $ type="remote flow source"
 
 $webclient = [System.Net.WebClient]::new()
-$data = $webclient.DownloadData("https://example.com/data.txt") # $ MISSING: type="remote flow source"
+$data = $webclient.DownloadData("https://example.com/data.txt") # $ type="remote flow source"