Added method to get an account by name

Breeze/src/Breeze.Wallet/Wallet.cs

@@ -125,6 +125,23 @@ namespace Breeze.Wallet
             var index = unusedAccounts.Min(a => a.Index);
             return unusedAccounts.Single(a => a.Index == index);
         }
+
+        /// <summary>
+        /// Gets the account matching the name passed as a parameter.
+        /// </summary>
+        /// <param name="accountName">The name of the account to get.</param>
+        /// <returns></returns>
+        /// <exception cref="System.Exception"></exception>
+        public HdAccount GetAccountByName(string accountName)
+        {
+            // get the account
+            HdAccount account = this.Accounts.SingleOrDefault(a => a.Name == accountName);
+            if (account == null)
+            {
+                throw new Exception($"No account with name {accountName} could be found.");
+            }
+            return account;
+        }
     }
 
     /// <summary>

Breeze/src/Breeze.Wallet/WalletManager.cs

@@ -210,11 +210,7 @@ namespace Breeze.Wallet
             Wallet wallet = this.GetWalletByName(walletName);
 
             // get the account
-            HdAccount account = wallet.AccountsRoot.Single(a => a.CoinType == coinType).Accounts.SingleOrDefault(a => a.Name == accountName);
-            if (account == null)
-            {
-                throw new Exception($"No account with name {accountName} could be found.");
-            }
+            HdAccount account = wallet.AccountsRoot.Single(a => a.CoinType == coinType).GetAccountByName(accountName);
 
             // validate address creation
             if (account.ExternalAddresses.Any())