refactor(maps): move the place clusters out of MapViewGL

The cluster source, its layers, the expansion zoom and the DOM bubbles
now live in placeClusterLayers.ts with their own tests, which brings
MapViewGL back under its size baseline instead of growing it. Lowers the
size and eslint baselines that this change made smaller.

client/src/components/Map/MapViewGL.test.tsx

@@ -1768,35 +1768,6 @@ describe('MapViewGL', () => {
     expect(drawn).not.toContainEqual([2.3, 48.3])
   })
 
-  // The bubbles are DOM so they share the Leaflet map's font and hover; the canvas
-  // layers under them stay only as the hit area.
-  it('FE-COMP-MAPVIEWGL-106: every cluster draws one HTML count bubble that zooms in on a click', async () => {
-    loadOnAttach()
-    projectAtDayZoom()
-    const clusterSource = { ...geoSource(), getClusterExpansionZoom: vi.fn(() => 11) }
-    glMap.getSource.mockImplementation((id: string) => (id === 'trip-place-clusters' ? clusterSource : null))
-    const cluster = { properties: { cluster_id: 5, point_count: 12 }, geometry: { coordinates: [139.7, 35.6] } }
-    glMap.querySourceFeatures.mockImplementation((_id: string, query?: { filter?: unknown[] }) =>
-      query?.filter?.[0] === 'has'
-        // The same cluster crossing a tile edge, and a feature without a count.
-        ? [cluster, cluster, { properties: { cluster_id: 6 }, geometry: { coordinates: [1, 1] } }]
-        : [])
-
-    render(<MapViewGL places={[buildMapPlace({ id: 81, lat: 35.6, lng: 139.7 })]} fitKey={1} />)
-    await flushFrames()
-
-    const bubbles = glMarkers.created.filter(m => m.element.querySelector('.marker-cluster-custom'))
-    expect(bubbles).toHaveLength(1)
-    expect(bubbles[0].lngLat).toEqual([139.7, 35.6])
-    expect(bubbles[0].element.textContent).toBe('12')
-
-    act(() => { bubbles[0].element.dispatchEvent(new MouseEvent('click', { bubbles: true })) })
-    expect(clusterSource.getClusterExpansionZoom).toHaveBeenCalledWith(5, expect.any(Function))
-    expect(glMap.easeTo).toHaveBeenCalledWith({ center: [139.7, 35.6], zoom: 11, duration: 350 })
-    glMap.querySourceFeatures.mockReset()
-    glMap.querySourceFeatures.mockReturnValue([])
-  })
-
   // One building modelled as several stops — drop the bags, check in, the museum inside
   // it — puts every pin on the same spot, and all but the top one are unreachable. There
   // is no spiderfy on a GL map, so the stack draws as the one pin worth seeing (#2344).