Add a map-level debug flag for Cesium maps

[robyngit]

This PR adds a map-level debug as well as a show3DTilesInspector option to Cesium map config.

When debug: true is set, the Cesium widget now:

• enables Cesium tile coordinate and grid imagery overlays
• shows the FPS counter
• hides globe skirts to make tile edges easier to inspect
• logs loaded/rendered/removed layer details to the console
• shows a small camera position overlay on the map

When show3DTilesInspector: true is set, the Cesium widget now:

• renders Cesium's built-in 3D Tiles inspector widget
• lazy-loads the inspector stylesheet only when the inspector is enabled

This change does not automatically enable layer-specific Cesium debug flags such as 3D Tiles debug properties passed through cesiumOptions.

It also adds a shared Utilities.formatFixedNumber() helper and uses it for the camera overlay formatting.

To test manually:

Debug mode:

1. Configure a Cesium map with debug: true in its map config.
2. Open a page that renders that Cesium map.
3. Confirm the map shows:
   • tile coordinate labels
   • grid imagery overlay
   • FPS counter
   • camera position overlay
4. Pan, zoom, and rotate the camera and confirm the camera overlay updates as the view changes.
5. Open the browser console and confirm layer information is logged when the map loads.
6. Set debug: false or remove the flag and confirm the debug overlays/counter/logging no longer appear.

3D Tiles inspector:

1. Configure a Cesium map with show3DTilesInspector: true in its map config.
2. Open a page that renders that Cesium map, ideally with a 3D Tiles layer.
3. Confirm the 3D Tiles inspector appears in the top-right of the map.
4. Expand and collapse inspector sections and confirm the widget is styled correctly.
5. Use the inspector controls and confirm they affect the loaded 3D Tileset as expected.
6. Disable show3DTilesInspector and confirm the inspector no longer appears.

[Copilot]

Pull request overview

This PR adds map-level Cesium debugging controls by introducing a debug flag and a show3DTilesInspector flag on the map configuration model, then wiring those options into CesiumWidgetView to enable built-in Cesium debug overlays and the 3D Tiles inspector (with lazy-loaded inspector CSS).

Changes:

• Add map config defaults and acceptance for debug and show3DTilesInspector.
• Enable Cesium debug helpers (FPS, grid/tile coordinates, skirts off, camera overlay, layer logging) and optionally render the 3D Tiles inspector with lazy-loaded CSS.
• Add a shared Utilities.formatFixedNumber() helper plus unit tests for the new behaviors.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test/js/specs/unit/views/maps/CesiumWidgetView.spec.js	Adds unit tests for debug mode and 3D Tiles inspector rendering/cleanup.
test/js/specs/unit/models/maps/Map.spec.js	Adds tests for new map config defaults and config acceptance.
test/js/specs/unit/common/Utilities.spec.js	Adds tests for the new numeric formatting utility.
src/js/views/maps/CesiumWidgetView.js	Implements debug-mode toggles, camera overlay formatting, inspector rendering, and debug logging hooks.
src/js/models/maps/Map.js	Documents and adds defaults for the new map-level config flags.
src/js/common/Utilities.js	Introduces formatFixedNumber() helper.
src/css/map-view.css	Styles the debug overlay, FPS counter container, and inspector container.
src/css/Cesium3DTilesInspector.css	Adds a Cesium inspector stylesheet intended to be lazy-loaded for the 3D Tiles inspector.

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[robyngit]

This feature has been tested by @justinkadi who has been using it extensively in a dev instance of MetacatUI.