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/immich-openapi-specs.json

@@ -5343,6 +5343,9 @@
           "metadataExtraction": {
             "$ref": "#/components/schemas/JobStatusDto"
           },
+          "migration": {
+            "$ref": "#/components/schemas/JobStatusDto"
+          },
           "objectTagging": {
             "$ref": "#/components/schemas/JobStatusDto"
           },
@@ -5372,6 +5375,7 @@
           "objectTagging",
           "clipEncoding",
           "storageTemplateMigration",
+          "migration",
           "backgroundTask",
           "search",
           "recognizeFaces",
@@ -6535,6 +6539,7 @@
           "clipEncoding",
           "backgroundTask",
           "storageTemplateMigration",
+          "migration",
           "search",
           "sidecar",
           "library"
@@ -7693,6 +7698,9 @@
           "metadataExtraction": {
             "$ref": "#/components/schemas/JobSettingsDto"
           },
+          "migration": {
+            "$ref": "#/components/schemas/JobSettingsDto"
+          },
           "objectTagging": {
             "$ref": "#/components/schemas/JobSettingsDto"
           },
@@ -7722,6 +7730,7 @@
           "objectTagging",
           "clipEncoding",
           "storageTemplateMigration",
+          "migration",
           "backgroundTask",
           "search",
           "recognizeFaces",