feat(location): render the search field's open and searching state from the tray

LocationControls presents whether the search field is open and whether a
lookup runs, and the dock renders its expanded and searching classes and
calls toggleSearch(). The lookup, the navigation's settle, Escape and the
location tray's collapse reach the field through the controls
(setSearching, settleSearch, closeSearch) instead of writing its classes.
LocationControls no longer takes searchToggle, LocationSearch takes
setSearching and NavigationController takes settleSearch in place of
searchInput.

src/panelEscape.test.mjs

@@ -151,17 +151,12 @@ test('a collapsed nested panel does not block the next Escape from closing its p
 
 test('Location Escape clears a hidden draft search before restoring disclosure focus', () => {
   const fixture = panelFixture({ id: 'location-bar' });
-  const removed = [];
-  let blurred = false;
-  fixture.manager._locationSearch = {
-    classList: { remove: (...names) => removed.push(...names) },
-    value: 'focus cleanup',
-    blur: () => { blurred = true; },
-  };
+  // The location controls close the field and drop its draft
+  // (src/ui/locationControls.test.mjs).
+  let closed = 0;
+  fixture.manager._closeLocationSearch = () => { closed += 1; };
   assert.equal(fixture.manager._collapsePanelOnEscape(fixture.event, 'location-bar'), true);
-  assert.deepEqual(removed, ['expanded']);
-  assert.equal(fixture.manager._locationSearch.value, '');
-  assert.equal(blurred, true);
+  assert.equal(closed, 1);
   assert.equal(fixture.focused(), true);
 });