further improve instance mangement UI

[phager-at]

We should discuss further improvements on instance management UI:

• add/edit rule instances via form displayed in modal instead of new page
  • more modern approach
  • should be quite easily be implementable if create external function for instance management #50 lands
• convert to reactive UI
  • most modern approach of creating UIs
  • could help with a live preview how the configured rule instances work as a whole given certain input data

[daledavies]

For the first option we could maybe use a modalform or dynamicform and still have a non-modal fallback. Ultimately if we convert this page to reactive UI I guess that's not an issue.

[phager-at]

We could try to combine progressive enhancements with a reactive UI. Never went from a non-JS fallback to a reactive UI myself, but it should be do-able. Most of the reactive UIs I did in the past loaded everything via AJAx from the start...