simplify registerFunction

[qicosmos]

Description

current registerFunction need to fill many argument types:

template <typename TExecParams>
struct MyPlusFunction {
  FOLLY_ALWAYS_INLINE void
  call(int64_t& out, const int64_t& a, const int64_t& b) {
    out = a + b;
  }
};

registerFunction<MyPlusFunction, int64_t, int64_t, int64_t>({"my_plus"});

I think it can be simplified:

registerFunction<MyPlusFunction>({"my_plus"});

Because the argument types can be trait by function traits.