New sanitizers: delete-names and derive-names

[lonvia]

This adds two new sanitizers:

• delete-names allows to remove names according to a pattern. This is a replacement for delete-tags with slightly more standardized parameter names.
• derive-names allows to create additional names by deriving them from an existing one. Can also be used to add names given certain conditions.

The delete-tags sanitizer is now deprecated and will be remove in the new major version.

Also cleans up the sanitizer code a little and adds additional check to avoid helper modules being loaded as a sanitizer.