Ingest different DRS formats

This PR is a significant rewrite of how we handle DRS file paths to allow us to ingest paths of a few different known DRS formats.

This involved:

• creating a new crate to handle just loading the different DRS types
• changing ingestion to load the different types and then convert them to our metadata format
• fix some funky issues with data-dir not behaving how it should
  • I also made it optional so not having it means that all datasets are ingested

freva/src/drs/ingest.rs

@@ -62,7 +62,7 @@ pub struct DatasetReport {
 pub async fn ingest<P: AsRef<Path>>(
     solr: &Solr,
     drs_conf: &Config,
-    data_dir: Option<P>,
+    data_dir: &Option<P>,
     batch_size: usize,
     files_collection: Option<&str>,
     latest_collection: Option<&str>,