Mbst 9831 basic monitoring

- Refactor of transaction store (enhanced statuses)
- some refactoring of xml generation
- Creation of feed stats and associated resolver
Welcome to the simple model. Unlike the rest of the simple model, it can't live in atlas-model, because it is the simple model for a class from feeds. This is one of the few cases for this, and hence it's unusual. This is how the rest of the simple model works - a sparse model, where fields are populated as needed, determined by the annotations specified.