Add option to generate parameter names

[jpenilla]

For more consistent cross-version comparisons it would be useful for codebook to be able to name parameters similarly to how it names the lvt.

If we don't apply any parameter names, we will get a different mess depending on the version ($$x or snowman emoji names).

And when using parchment, we don't have mappings for every snapshot, so there is a large amount of redundant diff each version from the mappings getting more or less in sync/complete.

Having codebook generate parameter names in a consistent manner would solve this problem and give us much cleaner diffs.