Add fee estimation call

Breeze.UI/src/app/shared/classes/fee-estimation.ts

+export class FeeEstimation {
+    constructor(walletName: string, accountName: string, destinationAddress: string, amount: string, feeType: string, allowUnconfirmed: boolean) {
+        this.walletName = walletName;
+        this.accountName = accountName;
+        this.destinationAddress = destinationAddress;
+        this.amount = amount;
+        this.feeType = feeType;
+        this.allowUnconfirmed = allowUnconfirmed;
+    }
+    
+    walletName: string;
+        accountName: string;
+        destinationAddress: string;
+        amount: string;
+        feeType: string;
+        allowUnconfirmed: boolean;
+    }
+    
\ No newline at end of file

Breeze.UI/src/app/shared/services/api.service.ts

@@ -14,6 +14,7 @@ import { WalletRecovery } from '../classes/wallet-recovery';
 import { WalletLoad } from '../classes/wallet-load';
 import { WalletInfo } from '../classes/wallet-info';
 import { Mnemonic } from '../classes/mnemonic';
+import { FeeEstimation } from '../classes/fee-estimation';
 import { TransactionBuilding } from '../classes/transaction-building';
 import { TransactionSending } from '../classes/transaction-sending';
 
@@ -227,6 +228,17 @@ export class ApiService {
         .map((response: Response) => response);
     }
 
+    /**
+     * Estimate the fee of a transaction
+     */
+    estimateFee(data: FeeEstimation): Observable<any> {
+      this.getCurrentCoin();
+      
+      return this.http
+        .post(this.currentApiUrl + '/wallet/estimate-txfee/', JSON.stringify(data), {headers: this.headers})
+        .map((response: Response) => response);
+    }
+
     /**
      * Build a transaction
      */