Make pke API and doc strings up-to-date with OpenFHE v1.2

[yspolyakov]

[dsuponitskiy]

added a corresponding issue in openfhe-development.

[dsuponitskiy]

Add:
MultiAddPubKeys
GetEvalAutomorphismKeyMap
MultiEvalAtIndexKeyGen
MultiAddEvalAutomorphismKeys

InsertEvalAutomorphismKey will not be added as it is to become a private function. InsertEvalSumKey() should be used instead.