chore(server): Store generated files (thumbnails, encoded video) in subdirectories (#4112)

* save thumbnails in subdirectories

* migration job, migrate assets and face thumbnails

* fix tests

* directory depth of two instead of three

* cleanup empty dirs after migration

* clean up empty dirs after migration, migrate people without assetId

* add job card for new migration job

* fix removeEmptyDirs race condition because of missing await

* cleanup empty directories after asset deletion

* move ensurePath to storage core

* rename jobs

* remove unnecessary property of IEntityJob

* use updated person getById, minor refactoring

* ensure that directory cleanup doesn't interfere with migration

* better description for job in ui

* fix remove directories when migration is done

* cleanup empty folders at start of migration

* fix: actually persist concurrency setting

* add comment explaining regex

* chore: cleanup

---------

Co-authored-by: Jason Rasmussen <jrasm91@gmail.com>

server/src/domain/system-config/system-config.core.ts

@@ -53,6 +53,7 @@ export const defaults = Object.freeze<SystemConfig>({
     [QueueName.SIDECAR]: { concurrency: 5 },
     [QueueName.LIBRARY]: { concurrency: 1 },
     [QueueName.STORAGE_TEMPLATE_MIGRATION]: { concurrency: 5 },
+    [QueueName.MIGRATION]: { concurrency: 5 },
     [QueueName.THUMBNAIL_GENERATION]: { concurrency: 5 },
     [QueueName.VIDEO_CONVERSION]: { concurrency: 1 },
   },