Add InTransaction() and GetTransaction() ext methods

Author: mythz

src/ServiceStack.OrmLite/OrmLiteConnection.cs

@@ -132,4 +132,13 @@ internal interface ISetDbTransaction
     {
         IDbTransaction Transaction { get; set; }
     }
+
+    public static class OrmLiteConnectionUtils
+    {
+        public static bool InTransaction(this IDbConnection db) => 
+            db is IHasDbTransaction setDb && setDb.DbTransaction != null;
+
+        public static IDbTransaction GetTransaction(this IDbConnection db) => 
+            db is IHasDbTransaction setDb ? setDb.DbTransaction : null;
+    }
 }

src/ServiceStack.OrmLite/OrmLiteTransaction.cs

@@ -17,8 +17,7 @@ public OrmLiteTransaction(IDbConnection db, IDbTransaction transaction)
             this.Transaction = transaction;
 
             //If OrmLite managed connection assign to connection, otherwise use OrmLiteContext
-            var ormLiteConn = this.db as ISetDbTransaction;
-            if (ormLiteConn != null)
+            if (this.db is ISetDbTransaction ormLiteConn)
             {
                 ormLiteConn.Transaction = this.Transaction = transaction;
             }
@@ -36,8 +35,7 @@ public void Dispose()
             }
             finally
             {
-                var ormLiteConn = this.db as ISetDbTransaction;
-                if (ormLiteConn != null)
+                if (this.db is ISetDbTransaction ormLiteConn)
                 {
                     ormLiteConn.Transaction = null;
                 }