Add parameter encoding helpers to NETWORK

This adds two more methods:
- `NETWORK:UrlEncode()`: Encode a single string value.
- `NETWORK:EncodeQueryParameters()`: Encode a table as query string.

Docs/Luadoc/Lua.xml

@@ -1110,6 +1110,8 @@
 		<Class name='NetworkManager'>
 			<Function name='IsUrlAllowed'/>
 			<Function name='HttpRequest'/>
+			<Function name='UrlEncode'/>
+			<Function name='EncodeQueryParameters'/>
 		</Class>
 		<Class name='NCSplineHandler'>
 			<Function name='get_spline'/>

Docs/Luadoc/LuaDocumentation.xml

@@ -3603,6 +3603,12 @@ NETWORK:HttpRequest{
 }
 </code></pre>
 	</Function>
+	<Function name='UrlEncode' return='string' arguments='string value'>
+		Returns the URL encoded representation of <code>value</code>.
+	</Function>
+	<Function name='EncodeQueryParameters' return='string' arguments='table query'>
+		Returns the <code>query</code> encoded as a query string. Keys and values are automatically URL encoded.
+	</Function>
 </Class>
 <Class name='NoteSkinManager'>
 	<Description>