Add Dynamic workloads for Scenarios

[AntyaDev]

Reference: https://github.com/PragmaticFlow/NBomber/discussions/662

NBomberRunner
    .RegisterScenarios(scenario1, scenario2)
    .WithLoadSimulations(loadSimulation, probablityDistribution: optional)

or

Scenario.Create("")
        .WithLoadSimulations()
        .WithProbability(3)