feat(panels): render each panel's state classes from the store

A panel's collapsed, dock-pinned, dock-pinned-top, layout-auto-collapsed
and accordion-collapsed classes are drawn by its root's v-panel-state from
the gev-panel-chrome store. PanelChrome, its restore, the layout
controller, both rails and the side accordion present each panel's state
there instead of writing its classes; the rails call onCollapse(panel,
{collapsed, auto}). The directive applies a change in a synchronous
watcher, since the rails measure a panel in the task that opens or closes
it.

Destroying the chrome inside Cockpit now puts back the panels Cockpit's
entry closed while it can still present them. Without a shell, the voice
tools' set_panel_open reports that there is no panel to open. QA scripts
present the states they set instead of writing the classes.

src/ui/applicationShell.js

@@ -234,8 +234,7 @@ export class StyleManager extends ShellFacade {
         _setCockpitDisclosure: (...args) => this._setCockpitDisclosure(...args),
         _cockpitDisclosureOpen: (kind) => this._cockpitDisclosureOpen(kind),
         _setMapStack: (...args) => this._setMapStack(...args),
-        _syncPanelCollapseButton: (...args) =>
-          this._syncPanelCollapseButton(...args),
+        _presentPanel: (...args) => this._presentPanel(...args),
         _syncShareState: (...args) => this._syncShareState(...args),
         setPanelCollapsed: (...args) => this.setPanelCollapsed(...args),
       },