Expose strategy flag in the ask function

[AkselObdrup]

The backend supports various strategies for the ask() function when the user want a batch of experiments.
Currently the default value of strategy is "stbr_fill", which means that after the first experiment has been drawn with the acqusition function the remaining experiments will be chosen with the Steinerberger strategy (which is a very explorative method).
It would often be useful to be able to switch to one of the other batch ask strategies, such as "stbr_full", "cl_min", "cl_mean", "cl_max" or "KB".
This could be implemented with a dropdown list in the Result data component and the choice should be saved in the JSON file eg. under extras like experimentSuggestionCount and then the ask call in the API should include this choice.