Open file hook

**is your feature request related to a problem? Please describe.**
I would like to open certain files in external programs,
like for example a docx in a onlyoffice document server,
or a jupyter notebook in jupyter, or a web-viewer for 3D models.
Or a WARC-replayer for web archives

**Describe the idea / solution you'd like**
When opening a file from the webui,
copyparty could invoke a hook,
which would then run some code -
likely requiring to make a share url of some sort to allow the external program to edit it.
Getting some sort of returned url and instructing the webui to open it in a tab.

I'm not sure how this would work with webdav or sftp and whatnot, maybe it'd be fine, as long as there are proper file-locks, but I'm not really sure if there are, there would have to be some way of marking file as busy, so the other interfaces won't try to write to it or something to that effect.

Related:
#423

查看 webui 中打开文件的逻辑，该逻辑可能位于 HTTP request handlers 中。该 hook 需要生成共享 URL 并处理文件锁。检查代码库中现有的文件锁定机制，了解 WebDAV 或 SFTP 等其他接口如何与文件交互。查看 issue #423 以了解相关背景。该功能需要理解服务器的架构，以便集成外部程序的启动和 URL 返回。

由索引模型根据 Issue 内容生成。