[Workbench] Ensure modal button order is consistent
These modals have the primary button first from the right:
These modals have the primary button first from the left:
- pipeline_instances/show.html.erb (two primary buttons)
- We prefer to do it like the Bootstrap examples: primary button(s) on the right.
- I think it's OK to have multiple primary buttons per modal. (This might be friendlier as a single "Copy" button, with a default-unchecked checkbox "run the new pipeline right away". If you forget to check the box, you can hit Run on the next page, so no biggie. But this change doesn't seem especially urgent.)