refactor(server): decouple generated images from image formats (#8246)

* rename

thumbnail config

update target paths, fix tests

rename to image settings

replace legacy enum

better typing

update sql

update api

remove config option

fix

* update docs

* update other thumbnail configs in migration

* keep legacy enum for now

* fix jumbled job names

* fix jumbled job names in tests

* rename thumbhash job

* rename dto

* fix tests

* preserve order

* remove unused import

* keep old fields in dto, marked deprecated

* update sql

---------

Co-authored-by: Alex Tran <alex.tran1502@gmail.com>

mobile/openapi/test/system_config_dto_test.dart

@@ -21,6 +21,11 @@ void main() {
       // TODO
     });
 
+    // SystemConfigImageDto image
+    test('to test the property `image`', () async {
+      // TODO
+    });
+
     // SystemConfigJobDto job
     test('to test the property `job`', () async {
       // TODO
@@ -81,11 +86,6 @@ void main() {
       // TODO
     });
 
-    // SystemConfigThumbnailDto thumbnail
-    test('to test the property `thumbnail`', () async {
-      // TODO
-    });
-
     // SystemConfigTrashDto trash
     test('to test the property `trash`', () async {
       // TODO