Set territory pattern on purchase (#1932)

## Description:

When purchasing a territory pattern, set it after successful purchase

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan

src/client/components/PatternButton.ts

@@ -16,7 +16,7 @@ export class PatternButton extends LitElement {
   onSelect?: (pattern: Pattern | null) => void;
 
   @property({ type: Function })
-  onPurchase?: (priceId: string) => void;
+  onPurchase?: (pattern: Pattern) => void;
 
   createRenderRoot() {
     return this;
@@ -40,7 +40,7 @@ export class PatternButton extends LitElement {
   private handlePurchase(e: Event) {
     e.stopPropagation();
     if (this.pattern?.product) {
-      this.onPurchase?.(this.pattern.product.priceId);
+      this.onPurchase?.(this.pattern);
     }
   }