Add functionality to cancel tickets

Introduces a cancel order confirmation dialog and integrates it into the order flow. Refactors error and success components to support singular/plural seat messaging and retry actions. Updates navigation and button behaviors for better user experience. Fixes minor UI and logic issues in reservation, purchase, and conversion flows.

src/app/selected-seats.service.ts

@@ -61,6 +61,7 @@ export class SelectedSeatsService {
   }
 
   commit(): void {
+    this.erroredSignal.set(false);
     this.committedSignal.set(true);
   }
 
@@ -69,6 +70,7 @@ export class SelectedSeatsService {
   }
 
   cancel(): void {
+    this.erroredSignal.set(false);
     this.cancelledSignal.set(true);
   }