[SPARK-3382] GradientDescent convergence tolerance

GrandientDescent can receive convergence tolerance value. Default value is 0.0.
When loss value becomes less than the tolerance which is set by user, iteration is terminated.
It is odd to have an API with 2 different argument orders.  Can this please be fixed in 1 of these 2 ways:
(1) Keep the old argument order, and have convergenceTolerance come after initialWeights.
(2) Remove this old method call completely, and update the code base where relevant.
I vote for (1) for consistency.