Only show unique badge titles in the Badge Title dropdown

Filter the preference Badge Title to only show unique badge title names.
https://meta.discourse.org/t/set-title-dialog-shows-multiple-instances-of-the-same-badge/19071
Only show unique badge titles in the Badge Title dropdown

Filter the preference Badge Title to only show unique badge title names.
Updated to use lodash
https://meta.discourse.org/t/set-title-dialog-shows-multiple-instances-of-the-same-badge/19071
Merge pull request #2672 from cpradio/master

Only show unique badge titles in the Badge Title dropdown