feat(core): add convert_file_src() — Rust equivalent of convertFileSrc()

[omair445]

Hey! I noticed there's no Rust-side equivalent of the JS convertFileSrc() function, so I went ahead and added one.

What this does

Adds a public tauri::convert_file_src() function that converts a local file path into an asset protocol URL that can be loaded by the webview. This mirrors the existing JavaScript convertFileSrc() behavior:

• Windows/Android: https://{protocol}.localhost/{encoded_path}
• macOS/Linux/iOS: {protocol}://localhost/{encoded_path}

Usage

// Default 'asset' protocol
let url = tauri::convert_file_src("/path/to/image.png", None);

// Custom protocol
let url = tauri::convert_file_src("/path/to/file.mp4", Some("stream"));

This is useful for Rust plugin authors and app developers who need to construct asset URLs from the backend without going through JS.

Closes #12022

[omair445]

Hey everyone, I am very very sorry I got stuck in work-related stuff and haven't been able to follow up on this. I am happy if anyone else can take care of this from here or if the maintainers want to push the final bits. Apologies again for the delay!

[Legend-Master]

Hey, thanks for contributing.

I am closing this since someone's already working on this at #14786 and the review is in progress