Implement NetworkManager

For now there are two methods:

- `NETWORK:IsUrlAllowed()`: Check whether access to a certain URL is allowed.
- `NETWORK:HttpRequest()`: Perform an HTTP request.

By default access to the network is disabled for all target hosts. It
can be enabled by setting `HttpEnable=1` in the preferences. Individual
hosts have to be added to `HttpAllowHosts` as a comma separated list to
allow access.

See included docs for more details on usage.

extern/IXWebSocket-11.3.2/test/IXStreamSqlTest.cpp

@@ -0,0 +1,42 @@
+/*
+ *  IXStreamSqlTest.cpp
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2020 Machine Zone. All rights reserved.
+ */
+
+#include "IXTest.h"
+#include "catch.hpp"
+#include <iostream>
+#include <ixsnake/IXStreamSql.h>
+#include <string.h>
+
+using namespace ix;
+
+namespace ix
+{
+    TEST_CASE("stream_sql", "[streamsql]")
+    {
+        SECTION("expression A")
+        {
+            snake::StreamSql streamSql(
+                "select * from subscriber_republished_v1_neo where session LIKE '%123456%'");
+
+            nlohmann::json msg = {{"session", "123456"}, {"id", "foo_id"}, {"timestamp", 12}};
+
+            CHECK(streamSql.match(msg));
+        }
+
+        SECTION("expression A")
+        {
+            snake::StreamSql streamSql("select * from `subscriber_republished_v1_neo` where "
+                                       "session = '30091320ed8d4e50b758f8409b83bed7'");
+
+            nlohmann::json msg = {{"session", "30091320ed8d4e50b758f8409b83bed7"},
+                                  {"id", "foo_id"},
+                                  {"timestamp", 12}};
+
+            CHECK(streamSql.match(msg));
+        }
+    }
+
+} // namespace ix