feat(SubwayStatus): Show effect if unique when combining Green Line rows

[joshlarson]

Scope

Asana Ticket: ⚠️ Update homepage subway status to support multiple GL branch station bypasses

Implementation

• When combining Green line rows, if their statuses are the same (e.g. they're both :station_closure), then show the label text for that status, rather than "⚠️ See Alerts".

Screenshots

• Left: Status from the alerts page, to show off the state of the world. This view doesn't collapse rows, so this PR doesn't change how that behaves.
• Middle: Current behavior on main (shown in dev-green so I could try out different combos). Notice how it indiscriminately collapses to "⚠️ See Alerts".
• Right: This branch. In the first image, the two "Stop Skipped" rows are combined into a single row that lists the two stops. In the second image, the three rows are combined into a single row that just says "3 Stops". In the third image, one of the alerts has a future start time, so they still get combined to "⚠️ See Alerts". In the fourth image, the alerts don't all have the same effect, so they still get combined to "⚠️ See Alerts".

How to test

Compare homepage subway status with alerts page subway status. Create alerts on different branches of the Green line with the same effects, and see that they show that effect (e.g. Stops Skipped). Create alerts with different effects or different start times and see that they still collapse to See Alerts. Try other scenarios that I didn't think of. Have fun!