Introduce a new IMainDomLock and both default and sql implementations

src/Umbraco.Core/Persistence/SqlSyntax/SqlServerSyntaxProvider.cs

@@ -250,6 +250,11 @@ where tbl.[name]=@0 and col.[name]=@1;", tableName, columnName)
         }
 
         public override void WriteLock(IDatabase db, params int[] lockIds)
+        {
+            WriteLock(db, 1800, lockIds);
+        }
+
+        public void WriteLock(IDatabase db, int millisecondsTimeout, params int[] lockIds)
         {
             // soon as we get Database, a transaction is started
 
@@ -260,7 +265,7 @@ where tbl.[name]=@0 and col.[name]=@1;", tableName, columnName)
             // *not* using a unique 'WHERE IN' query here because the *order* of lockIds is important to avoid deadlocks
             foreach (var lockId in lockIds)
             {
-                db.Execute(@"SET LOCK_TIMEOUT 1800;");
+                db.Execute($"SET LOCK_TIMEOUT {millisecondsTimeout};");
                 var i = db.Execute(@"UPDATE umbracoLock WITH (REPEATABLEREAD) SET value = (CASE WHEN (value=1) THEN -1 ELSE 1 END) WHERE id=@id", new { id = lockId });
                 if (i == 0) // ensure we are actually locking!
                     throw new ArgumentException($"LockObject with id={lockId} does not exist.");