feat: Display/hide left keyboard half and merged/unmerged state (#987)

* feat: Display/hide left keyboard half and merged/unmerged state

* feat: improve the animation

* feat: decrease left fade animation time

packages/uhk-common/src/models/device-connection-state.ts

@@ -1,4 +1,5 @@
 import { UdevRulesInfo } from './udev-rules-info';
+import { HalvesInfo } from './halves-info';
 
 export interface DeviceConnectionState {
     connected: boolean;
@@ -6,4 +7,5 @@ export interface DeviceConnectionState {
     bootloaderActive: boolean;
     zeroInterfaceAvailable: boolean;
     udevRulesInfo: UdevRulesInfo;
+    halvesInfo: HalvesInfo;
 }

packages/uhk-common/src/models/halves-info.ts

@@ -0,0 +1,4 @@
+export interface HalvesInfo {
+    areHalvesMerged: boolean;
+    isLeftHalfConnected: boolean;
+}

packages/uhk-common/src/models/index.ts

@@ -11,3 +11,4 @@ export * from './hardware-module-info';
 export * from './save-user-configuration-data';
 export * from './udev-rules-info';
 export * from './update-firmware-data';
+export * from './halves-info';