[Feature]: Let the file input box to support uploading multiple files

[LuoTianOrange]

Describe the feature

I used to use element-plus, which provided an Upload component for uploading files, allowing me to choose between uploading single or multiple files.When I wanted to upload multiple images using a component, I found that only the input component could upload files, and only one file could be uploaded at a time. It would be great if it could support uploading multiple files.

Additional information

• I intend to submit a PR for this feature.
• I have already implemented and/or tested this feature.