GraphQLTest: Add Proxy config

GUIs.Test.GraphQLTest/Config.vb

@@ -5,4 +5,17 @@
     Public Property Email As String = "foo.bar@wisag.de"
     Public Property Password As String = "Password"
     Public Property BaseUrl As String = "https://data.api.wisag.de:8443"
+
+    Public Property ProxyHost As String = ""
+    Public Property ProxyPort As Integer = 0
+    Public Property ProxyUsername As String = ""
+    Public Property ProxyPassword As String = ""
+
+    Public Function HasProxySet() As Boolean
+        Return ProxyHost <> "" And ProxyPort > 0
+    End Function
+
+    Public Function HasProxyCredentialsSet() As Boolean
+        Return ProxyUsername <> "" And ProxyPassword <> ""
+    End Function
 End Class