extensibility: rules engine (#511)

* rules format prototype

* config container

* lightweight rules

* fdescribe

* basic rule integration

* migrate "create folder" to click actions

* migrate toolbar to new action handlers

* rule support for "create folder" (toolbar)

* upgrade "View" toolbar command

* migrate to rules

* cleanup tests

src/app/components/sidenav/sidenav.component.html

@@ -10,7 +10,7 @@
                     <button *ngFor="let entry of createActions"
                         mat-menu-item
                         [disabled]="entry.disabled"
-                        (click)="runAction(entry.target.action)">
+                        (click)="runAction(entry.actions.click)">
                         <mat-icon>{{ entry.icon }}</mat-icon>
                         <span>{{ entry.title | translate }}</span>
                     </button>