Enhancements for batch mode

[NJLangley]

Been working with the official batch mode implementation for a few weeks now, I think there are a few things that would be great additions.

• Adding a sort order to batch stage link. Sometimes we split a stage in two for a new dependency, and having a new stage with a auto-assigned id means it runs after the existing stages, which can take a fair bit of time to fix. For non batch mode the sort order could remain the stage id.
• Adding the stage name and above sort order to the current execution and execution log tables. If the stage id's hav4e changed over time, the reporting views on them can break when looking up the stage name
• Override Restart property. This is currently at the framework level, but would be more useful at the batch level, so we can clear down and restart a single batch while another runs
• Precursor stored procedure. Same as above, would be useful to have this defined at the batch level in batch mode
• Add the batch name as a parameter in the child and infant pipelines. Although this would not actually be used by those pipelines for anything, it would allow showing the batch name against all running pipelines in the ADF monitoring view

Happy to contribute the code for these