Implement all Figma designs

I'll use this bug to track discrepancy between UI designs in Figma and reality. Was trying https://github.com/dabreegster/abstreet/projects/7 for a while, but issues are easier to maintain.

- [x] Click individual intersections in the multi signal sidepanel to jump to that intersection
- [x] New traffic signal editor: crosswalks
- [x] New traffic signal editor: tune arrow style
- [x] Cancel out of traffic signal editor (go straight back to simulation?)
- [x] Fix inactive button height (file save)
- [x] The great button overhaul
- [x] File save dialog (don't allow overwriting)
- [ ] Bulk edit results (show errors)
- [x] Bulk edit lanes needs an adder/remover for lane type transformations
- [ ] Edit mode loader in the main sandbox screen, near "traffic"
- [x] More detailed agent meter tooltips
- [ ] Minimap filters
- [x] Agent intention bubbles (need to plumb trip purpose for some of them)
- [ ] Align zoom in/out controller with pedestrian minimap checkbox
- [ ] New trip table
- [x] Access signal demand dashboard from intersection info panels and also map overlays
- [x] Use ▼ or SVG for dropdowns again
- [ ] Throughput line plot changes
- [ ] Audit/update language everywhere: "vehicles" and "commuters". Details on notion.
- [x] Audit/update numeric precision -- times and durations and most things can be rounded to whole numbers
- [x] Don't clip tooltips to scrollable panels
- [ ] New agent info panels
- [ ] New trip summaries

And a few more from #551:

- [ ] Allow the layers panel to be minimized. Always open a new one full; don't be sticky.
- [ ] Enable the info panel and layer panel to be draggable.
- [ ] Blur beneath the panels instead of increasing opacity so much
- [ ] Launch Santa and the 15m tool from the main menu of A/B Street, even though they're now separate apps
- [ ] Manually minimize the minimap when zoomed in. This decision is sticky.

Dieses Issue ist eine übergeordnete Tracking-Liste für UI/UX-Änderungen zur Angleichung an die Figma-Designs. Beginne damit, das verknüpfte Projekt-Board und den vorhandenen UI-Code zu untersuchen, der sich wahrscheinlich in den Crates `widgetry` oder `map_gui` befindet. Für jede Teilaufgabe muss die relevante UI-Komponente gefunden, mit dem Figma-Design verglichen und müssen Änderungen implementiert werden. „Done“ bedeutet, dass die UI mit der Design-Spezifikation übereinstimmt und alle vorhandenen UI-Tests besteht.

Vom Indexierungsmodell aus dem Issue-Text verfasst.