feat: make double tap to hold layer optional per key (#662)

* feat: make double tap to hold layer optional per key

* test: fix test serializer

* fix: remove "application start" text

* Add double-tap.svg

* Add closing dot at the end of the sentence.

* fead: add double-tap icon

* Bundle firmware version 8.3.0

* feat: 'layer-double-tap' feature flag

* feat: convert SwitchLayerMode to string enum

packages/uhk-web/src/app/components/popover/popover.component.html

@@ -55,6 +55,7 @@
         <layer-tab #tab *ngSwitchCase="tabName.Layer" class="popover-content"
                    [defaultKeyAction]="defaultKeyAction"
                    [currentLayer]="currentLayer"
+                   [allowLayerDoubleTap]="allowLayerDoubleTap"
                    (validAction)="keyActionValid=$event"
         ></layer-tab>
         <mouse-tab #tab *ngSwitchCase="tabName.Mouse" class="popover-content"