Design the view-mode functionality

[craigfowler]

Several tickets for the reports are based on view-mode functionality. This needs to be designed.

[craigfowler]

Features & scenarios

Based on what I have now. But, indent at each level of nesting to make it more clear. Smaller indent on mobile.

Add expand all/collapse all links

Add "Show only" check boxes. These become a drop down selection (multi-select) in mobile mode.

Errors

Rather than reporting on scenarios, just pluck out unique performables which have errors.

Show a count of how much each error reoccurs, with the ability to expand that to show which features/scenarios it affects.

Need to figure out how I identify a unique error. Maybe just use the performable type. Maybe use the report message too.

Performable types

TODO

Assets

List the assets by scenario.

Provide download links and (for supported types) previews.

Include "only successful scenarios" and "only failed scenarios" toggles.