Add wildcard search functionality

Currently the search function of taxonomy manager only allows you to search for an existing term via an exact match.

Wildcard search functionality would allow the admin to find all terms containing a particular string and easily compare them, and potentially merge or perform other actions on that subset of terms.

I am thinking of functionality similar to that available for searching for path aliases.

A use case for this functionality is most often found with free tagging vocabularies where users may have forgotten to use commas, or used similar but not exactly the same terms, and an admin wants to clean those terms up. For example, terms such as "drupal" "Drupal" "Planet Drupal" "Drupal Planet" "planetdrupal" "drupalplanet" would all likely appear on at least 2 different pages of the taxonomy manager. An admin may want to search for all terms containing "drupal" and then merge or otherwise clean them up.