Mirrors the C++ enum KeySwitchTechnique in pke/constants-defs.h.
Value
A named list of 3 integer scalars, each the value of the
OpenFHE C++ enumerator of the same name. BV selects the
Brakerski-Vaikuntanathan digit-decomposition key switch and
HYBRID the hybrid variant, which is the usual choice;
INVALID_KS_TECH marks an unset value. Pass an element as the
key_switch_technique argument of CKKSParams(), BFVParams(),
BGVParams() or fhe_context().