Update NSG theme, also refactor some code

src/graphics/omnibar/components/Ticker/Prize.vue

@@ -62,7 +62,7 @@ export default class extends Vue {
   }
 
   get symbol(): string {
-    return nodecg.bundleConfig.event.currency?.symbol || '$';
+    return nodecg.bundleConfig.event.currency.symbol || '$';
   }
 
   async created(): Promise<void> {

src/graphics/omnibar/components/Total.vue

@@ -155,8 +155,8 @@ export default class extends Vue {
 
   get totalStr(): string {
     // "Reset" value every 10k, specific to ESA Legends 2023.
-    const symbol = nodecg.bundleConfig.event.currency.symbol;
+    const { symbol } = nodecg.bundleConfig.event.currency;
-    const countryCode = nodecg.bundleConfig.event.currency.countryCode;
+    const { countryCode } = nodecg.bundleConfig.event.currency;
 
     const esal23 = nodecg.bundleConfig.event.shorts === 'esal23';