Add WebDAV asset upload

[bltavares]

Hi there, thank you for the project. I'm evaluating my options to build a simple backend for a garage sale website and I'm considering Trailbase for it.

As Trailbase is built as a single binary with bultin asset serving it seemed like a great fit.
To make it easier to upload the files, I was considering pairing trailbase with a simple HTTP File Server with WebDAV support. That way I could use something like rclone to upload the assets.

I was wondering if it would be possible to support WebDAV directly on the project, that way users can rclone directly to Trailbase asset directory and keep it as a single binary service.

I've attempted to use the WASM plugin interface to put a prototype of the feature together, but WebDAV use additional HTTP Verbs not supported by the plugin interface. For now, I'll go forward with the WebDAV "sidecar" but I thought of suggesting this feature to differentiate it from other options.

Maybe it could be done builtin (I imagine the filesystem is isolated per WASM component), or by extending the WASM API to accept a wildcard handler function without requiring an HTTP method mapping

Thanks anyway

[bltavares]

As discussed over the exploratory PR, it would be better to extend this using the WASM extension method. To do so, it would need additional extension points to consider to enable such extension.

[ignatz]

It's a bit unclear to me how the WASM plugin can read config options at this moment also, even if it's env environments/cli args.

Besides the dashboard, the latest release v0.32.0 also contains a "shared preferences" mechanism (we talked about on the PR), which should help.

Love to hear what your latest thoughts are.