Implemented manifest generation for EB full curation in ingest_envoy

Along the way:

• Added tests for partial-curation manifest generation for ingest_envoy
• Separated IngestionManifestBuilder's directory-to-search (staging_source_dir for ingestion, curation_source for curation) from the directory it wants to put its manifest in since partial curation doesn't always have the former.

apps/cli/executables/pexable/ingest_envoy/ingest_envoy/ingestion_manifest.py

@@ -194,9 +194,7 @@ class IngestionManifest(ManifestComponentIF):
         :return:
         """
         me_dict = self.to_dict()
-        if self.reingest is not None and not self.reingest.targets:
-            output_path = Path.cwd() / CURATOR_MANIFEST_FILENAME
-        elif self.reingest is not None:
+        if self.reingest is not None:
             output_path = self.destination_dir / CURATOR_MANIFEST_FILENAME
         else:
             output_path = self.destination_dir / MANIFEST_FILENAME