Possible to dynamically define cache directory?

Nobody has claimed this yet.

How would I go about setting up a dynamic cache directory? e.g.

```yaml
resolvers:
media_cache:
flysystem:
filesystem_service: oneup_flysystem.media_filesystem
cache_prefix: '_cache/'
```

Is there a service I can override perhaps?

Thanks

Start by tracing the `media_cache` resolver configuration, especially `filesystem_service` and `cache_prefix`, and identify whether the referenced service can be overridden. Review how the Flysystem resolver consumes these settings and define done as supporting a dynamic cache-directory value or documenting that service-based customization is required.

Written by the indexing model from the issue text.