[ServiceStudio] Add web service namespace property

Add a web service namespace property, to allow the change of the web service 
namespace uri.

Example

<myWebServiceMethod xmlns="https://www.outsystems.com">

By default the namespace Uri is set to https://www.outsystems.com unless its changed by the developer. (This allows outsystems to keep the standard behaviour, but will also allow for flexiability to change the web service namespace so it could be exposed to 3rd party and function as a public web service API).