feat(crossseed): Target indexer available on "Auto-search on completion" as well

**Is your feature request related to a problem? Please describe.**
In the RSS Automation we can pick what Target indexers we like to use

**Describe the solution you'd like**
Have the same option in "Auto-search on completion", as it currently only have cats/tags

This would allow us to pick per client which indexers to include on completion. 