Implement our own Meilisearch macros

[woller]

Instead of relying on meilisearch-rails for setting searchable data, it would be nice to have another set of macros specifically for this gem. This would also allow users of the gem to use meilisearch for other things.

The macro should (somehow) scope all values specifically for Kommandant or allow for the data to be stored on a separate meilisearch server.