Random seed needs to be of type integer

Describe the bug

The randomSeed attribute in the StochasticDistribution should have been an integer, but now it's a double. See https://code.asam.net/simulation/standard/openscenario/-/issues/197#note_4422

Also normally one seed is necessary to genreate one every concrete scenario, while here we only define one seed for one logical scenario, out of which a set of concrete scenarios should be generated. We have to reevaluate the concept how this should work. The goal should be to have exchangeable logical scenarios, so if they are executed in different test environments, the same concrete scenarios are generated out of them.

Describe the expected behavior

Change type to integer.