Check if anything should be changed in the multiparty logic for EvalAutomorphismKeyGen (to avoid duplicate generation of keys)

[yspolyakov]

Check whether any changes are needed due to #545 and #546

[yspolyakov]

InsertEvalAutomorphismKey avoids deduplication at the last stage of inserting the auto keys into the map. So this part is already addressed.

A duplication of keys is possible if the developer uses MultiEvalSumKeyGen or MultiEvalAtIndexKeyGen. The most efficient way would be to use MultiEvalAtIndexKeyGen once with the full list of indices. Maybe we can come up with a simpler way?