Remove the need for a XmlrpcStruct

[SchoolGuy]

This is currently looking like:

serializeMethodCall('function_name', [{'members': [{name: "data1", value: 0}, {name: 'data2', value: 0}]}])

my proposal to solve this issue is to allow objects of type map. However we need to ensure that the map is flat. It is allowed according to the XML-RPC Spec that you have a Map with different types. Thus something similar to the following should be possible:

const myMap = new Map<string, string|number|boolean|Date|ArrayBuffer>()
myMap.set("key", "value")
// More code...
serializeMethodCall('function_name', [myMap])