Mirrors the C++ enum ExecutionMode in pke/constants-defs.h.
Value
A named list of 2 integer scalars, each the value of the
OpenFHE C++ enumerator of the same name: EXEC_EVALUATION runs the
computation normally, while EXEC_NOISE_ESTIMATION runs it only to
measure the noise growth, which is the first of the two passes
needed when decryption uses noise flooding. Pass an element as the
execution_mode argument of CKKSParams() or fhe_context().