feat(server,web): system config for admin (#959)

* feat: add admin config module for user configured config, uses it for ffmpeg

* feat: add api endpoint to retrieve admin config settings and values

* feat: add settings panel to admin page on web (wip)

* feat: add api endpoint to update the admin config

* chore: re-generate openapi spec after rebase

* refactor: move from admin config to system config naming

* chore: move away from UseGuards to new @Authenticated decorator

* style: dark mode styling for lists and fix conflicting colors

* wip: 2 column design, no edit button

* refactor: system config

* chore: generate open api

* chore: rm broken test

* chore: cleanup types

* refactor: config module names

Co-authored-by: Zack Pollard <zackpollard@ymail.com>
Co-authored-by: Zack Pollard <zack.pollard@moonpig.com>

mobile/openapi/.openapi-generator/FILES

@@ -59,6 +59,10 @@ doc/ServerStatsResponseDto.md
 doc/ServerVersionReponseDto.md
 doc/SignUpDto.md
 doc/SmartInfoResponseDto.md
+doc/SystemConfigApi.md
+doc/SystemConfigKey.md
+doc/SystemConfigResponseDto.md
+doc/SystemConfigResponseItem.md
 doc/ThumbnailFormat.md
 doc/TimeGroupEnum.md
 doc/UpdateAlbumDto.md
@@ -79,6 +83,7 @@ lib/api/device_info_api.dart
 lib/api/job_api.dart
 lib/api/o_auth_api.dart
 lib/api/server_info_api.dart
+lib/api/system_config_api.dart
 lib/api/user_api.dart
 lib/api_client.dart
 lib/api_exception.dart
@@ -138,6 +143,9 @@ lib/model/server_stats_response_dto.dart
 lib/model/server_version_reponse_dto.dart
 lib/model/sign_up_dto.dart
 lib/model/smart_info_response_dto.dart
+lib/model/system_config_key.dart
+lib/model/system_config_response_dto.dart
+lib/model/system_config_response_item.dart
 lib/model/thumbnail_format.dart
 lib/model/time_group_enum.dart
 lib/model/update_album_dto.dart