Fixes #14636 - correctly search puppet class on host form

Searching for puppet classes that were ellipsized did not work as
expected on the host edit form. This was due to the search looking only
in the span content which was truncated and did not contain the entire
puppet class name. Also, cleaned up the js code to be clearer and more
efficiant.

(cherry picked from commit 0aacf3304d8d36fcd4d593036bdc64d02cc3112b)