[Feature] Implement better seed setting.

[gebauerm]

Seed setting is identical for all called objectives.
https://github.com/gebauerm/rapidFlow/blob/main/rapidflow/objective.py

Even when different seeds between different study rus are set, the objective will be called with the same seeds again.

"per_study" - new seeds for every conducted study
"constant" - constant seeds in every study
"no seeds" - no seeds before a call
Implement a simple seed setter for this.