Create an lc_facet field in the traject config

[rladdusaw]

User story

In order for the blacklgiht-hierarchy gem to work we need a new field with the property formatted data

Acceptance criteria

• If this change touches any of the files referenced in .rubocop_todo.yml create a new ticket to address the rubocop todo.
• the traject_config.rb file has a method to create the desired field

Implementation notes, if any

The current implementation uses these methods to create a set of fields. Add a field that has two values

"lc_facet": [ "J - Political Science", "J - Political Science:JQ - Political Institutions (Asia, Africa, Australia, Pacific Area)" ]

The first is the same as the lc_1letter_facet field and the second is the lc_1letter_facet concatenated to the lc_rest_facet with a colon as a delimiter.