Allow initial guess for the Brute Force algorithm of Minimal Fatal Shock

[Datseris]

Describe the feature you'd like to have

Some dynamical systems have simple enough basins and/or are low dimensional enough that the brute force approach is faster and more accurate. Additionally if one has a good initial guess of the norm or direction of the shock, then the algorithm can be even faster.

Only the black box optimization version allows for a user-provided initial guess. We should augment the brute force version with this possibility as well. If an initial guess is given then the first step of randomly searching for vectors is skipped, and we go directly into the second step of step by step decreasing the radius.