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/doc/SystemConfigDto.md

@@ -9,6 +9,7 @@ import 'package:openapi/api.dart';
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 **ffmpeg** | [**SystemConfigFFmpegDto**](SystemConfigFFmpegDto.md) |  | 
+**image** | [**SystemConfigImageDto**](SystemConfigImageDto.md) |  | 
 **job** | [**SystemConfigJobDto**](SystemConfigJobDto.md) |  | 
 **library_** | [**SystemConfigLibraryDto**](SystemConfigLibraryDto.md) |  | 
 **logging** | [**SystemConfigLoggingDto**](SystemConfigLoggingDto.md) |  | 
@@ -21,7 +22,6 @@ Name | Type | Description | Notes
 **server** | [**SystemConfigServerDto**](SystemConfigServerDto.md) |  | 
 **storageTemplate** | [**SystemConfigStorageTemplateDto**](SystemConfigStorageTemplateDto.md) |  | 
 **theme** | [**SystemConfigThemeDto**](SystemConfigThemeDto.md) |  | 
-**thumbnail** | [**SystemConfigThumbnailDto**](SystemConfigThumbnailDto.md) |  | 
 **trash** | [**SystemConfigTrashDto**](SystemConfigTrashDto.md) |  | 
 **user** | [**SystemConfigUserDto**](SystemConfigUserDto.md) |  |