Save the kernel parameters after warmup

[rlouf]

mcx/mcx/inference/hmc.py

Lines 198 to 205 in 2a2b948

	parameters = HMCParameters(
	jnp.ones(initial_state.position.shape[0], dtype=jnp.int32)
	* num_integration_steps,
	step_size,
	inverse_mass_matrix,
	)
	return last_chain_state, parameters, warmup_chain

We currently pass the parameters directly to the runtime; While the values of the parameters are passed in the Trace object, it would be convenient to update the Kernel's parameter values.