They cause warnings in every module even if they are not used, so just
remove them. We can still add them back if someone complains.

__CLASS__ is seemingly used nowhere currently. Which is good because it
definitely does not give you only a class name.

This one accepts a suitable std::initializer_list to allow for automatic
creation of parameters of more complex braced lists such as

```
void foo(const Parameter& param);

foo({{"key_1", {0., 1.}}, {"key_2", {2.}}});
```