Set default parameters for LWE ops

This pass adds default parameters to all lwe types as the lwe_params attribute, and for lwe ops as the params attribute, overriding any existing attributes set with those names.

This pass is primarily for testing purposes, and as a parameter provider before a proper parameter selection mechanism is added. This pass should not be used in production.

The specific parameters are hard-coded in lib/Dialect/LWE/Transforms/SetDefaultParameters.cpp.