Give the Cesium renderer the contract's input port

src/render/cesium/input.js feeds the shared router from one
ScreenSpaceEventHandler: every button's press, release and click, double
clicks, moves and pinches, under any one modifier. The DOM event being
dispatched gives the full modifiers and pointer type; an action Cesium
raises on a timer takes its own modifier. Wheel comes from the canvas in
lines and is never cancelled. Clicks are picked once, lazily, through the
query port. Cesium ends every held button on any release; those presses
end there, but only the button released clicks.

The viewer's stock select and follow move off its handler and run first,
as they did, but only for a press no lease took and while not suppressed.
Camera holds go through the scene's shared holds, ctrlWheelZoom through
ctrlWheelZoom.js. The router gains a before-hook and dispose, which stops
delivery mid-event.

The conformance renderer exposes the port and the harness feeds it;
input.lease, input.lease.grab, input.lease.press, input.clickPick and
input.behaviours join the Cesium checks.

scripts/format-scope.json

@@ -51,6 +51,8 @@
   "src/render/cesium/internals.js",
   "src/render/cesium/cameraInput.js",
   "src/render/cesium/ctrlWheelZoom.js",
+  "src/render/cesium/input.js",
+  "src/render/cesium/input.test.mjs",
   "src/render/cesium/cameraInput.test.mjs",
   "src/render/input/router.js",
   "src/render/input/router.test.mjs",