Incorporate legacy traffic metadata to Plausible.io

[astrochun]

User story

As a data creator from ages ago, I would like to see past views/downloads available through the Solr core queries within the PDC Discovery. This is possible using a CSV import:
https://plausible.io/docs/csv-import

Acceptance criteria

• If this change touches any of the files referenced in .rubocop_todo.yml create a new ticket to address the rubocop todo.
• I can successfully use this feature with Voice Over in Safari.
• I have checked this feature using one of the following browser extensions and confirmed that it does not add any level A or level AA issues:
  • axe dev tools
  • Lighthouse
  • Wave
• ...

Concrete example

Implementation notes, if any

[kelynch]

Method for extracting usage stats from DataSpace outlined in pulibrary/dspace-development#782