feat(Dropbox): add Dropbox adapter with file management capabilities and localization support

web/src/i18n/locales/en.json

@@ -499,6 +499,7 @@
   "/ or /drive": "/ or /drive",
   "Adapter Config": "Adapter Config",
   "adapter.type.local": "Local Filesystem",
+  "adapter.type.dropbox": "Dropbox",
   "adapter.type.webdav": "WebDAV",
   "adapter.type.googledrive": "Google Drive",
   "adapter.type.onedrive": "OneDrive",

web/src/i18n/locales/zh.json

@@ -487,6 +487,7 @@
   "/ or /drive": "/或/drive",
   "Adapter Config": "适配器配置",
   "adapter.type.local": "本地文件系统",
+  "adapter.type.dropbox": "Dropbox",
   "adapter.type.quark": "夸克网盘",
   "adapter.type.alist": "AList",
   "adapter.type.openlist": "OpenList",