Create a well defined intermediate test data structure format

[MikeNeilson]

Component to be refactored
Things downstream of gherkin file processing.

Purpose of refactoring
The KiwiTCMS system provides for a very well structured concept of test cases, plans, components, versions, etc. However, not all TCMSes are the same.

In getting things to work for the gradle plugin and Kiwi I already had to add another "callback" function for stream processing to fill in details.

Having a generic format would make it easier to test the gherkin processing code itself, we'd have a defined target, and then when time to convert we have all the possible information in some way. One issue in the current scheme was that the file information a feature is in is not available to the gradle plugin, where I opted to allow a "marker" value to be generated from. This is used for uniqueness as the Kiwi system is a bit weird. originally it defaulted to the file but during tests a temp directory was used so each case kept getting added.

Proposed method
Instead of the current Kiwi Specific structures that use a lot of Strings to be more generic, define an intermediary Test System data structures that would also include feature information.

the Stream processing would return these processed structures for the downstream system to consume and convert as necessary.

Additional context
Add any other context or screenshots about the feature request here.