[accelerator] handle temporarily unavailable state

frontend/src/app/components/accelerate-checkout/accelerate-checkout.component.scss

@@ -195,4 +195,5 @@
   right: 0;
   font-size: 12px;
   color: var(--red);
+  white-space: nowrap;
 }

frontend/src/app/components/accelerate-checkout/accelerate-checkout.component.ts

@@ -23,6 +23,7 @@ export type AccelerationEstimate = {
   vsizeFee: number;
   pools: number[];
   availablePaymentMethods: {[method: string]: {min: number, max: number}};
+  unavailable?: boolean;
 }
 export type TxSummary = {
   txid: string; // txid of the current transaction
@@ -259,6 +260,9 @@ export class AccelerateCheckout implements OnInit, OnDestroy {
               this.quoteError = `not_enough_balance`;
             }
           }
+          if (this.estimate.unavailable) {
+            this.quoteError = `temporarily_unavailable`;
+          }
           this.hasAncestors = this.estimate.txSummary.ancestorCount > 1;
           this.etaInfo$ = this.etaService.getProjectedEtaObservable(this.estimate, this.miningStats);