feat(refresh-webcam): Refresh webcam view on focus

Computers with agressive power management policies
tend to stop the webcam feed after getting to sleep.

This forces the webcam feed to be restarted on focus.

src/components/panels/WebcamPanel.vue

@@ -12,7 +12,7 @@
             </v-toolbar-title>
         </v-toolbar>
         <v-card-text class="px-0 py-0 content">
-            <img :src="webcamConfig.url" class="webcamImage" :style="webcamStyle" />
+            <img :src="url" class="webcamImage" :style="webcamStyle" />
         </v-card-text>
     </v-card>
 </template>
@@ -21,6 +21,21 @@
     import { mapState } from 'vuex'
 
     export default {
+        data: function() {
+            return {
+                refresh: 0
+            }
+        },
+        created: function () {
+            const handleRefreshChange = () => {
+                if (!document.hidden) {
+                    this.refresh = Math.ceil(Math.random() * Math.pow(10, 12))
+                }
+            }
+
+            document.addEventListener("focus", () => handleRefreshChange(), false);
+            document.addEventListener("visibilitychange", handleRefreshChange, false);
+        },
         components: {
 
         },
@@ -28,6 +43,12 @@
             ...mapState({
                 'webcamConfig': state => state.gui.webcam
             }),
+            url() {
+                    const url = this.webcamConfig.url
+                    const params = new URLSearchParams(url);
+                    params.set('bypassCache', this.refresh);
+                    return decodeURIComponent(params)
+            },
             webcamStyle() {
                 var transforms = '';
                 if (this.webcamConfig.flipX) {