`Algorithm.read_probe` should be removed

Any read_probe function of any algorithm is deprecated and no longer used, after bob.bio.base!78 (merged) is merged. It would be good to remove them.

This includes changing the according test cases, which need to be updated before bob.bio.base!78 (merged) can be merged.

created branch 23-algorithm-read_probe-should-be-removed

mentioned in merge request !29 (merged)

closed via commit 7a237630

closed via merge request !29 (merged)