feat: add the initial administration panel

[Angelmmiguel]

As Wasm Workers Server is evolving, we want to start adding an UI to start managing it. I'm really happy to open this PR as an initial version of that UI 😄. This admin panel is enabled via the --enable-panel flag and the UI looks like this:

$ wws https://github.com/vmware-labs/wasm-workers-server.git --git-folder "examples/python-basic" -i --enable-panel
⚙️  Preparing the project from: https://github.com/vmware-labs/wasm-workers-server.git
⚙️  Checking local configuration...
🚀 Installing: wasmlabs - python / 3.11.1+20230217
✅ Done
⚙️  Loading routes from: /tmp/dd21e3cd6d0f515301e1c7070e562af06074d9e8d10566179f97dba47e74cec9/examples/python-basic
⏳ Loading workers from 1 routes...
✅ Workers loaded in 489.699125ms.
    - http://127.0.0.1:8080/
      => /tmp/dd21e3cd6d0f515301e1c7070e562af06074d9e8d10566179f97dba47e74cec9/examples/python-basic/index.py
🎛️  The admin panel is available at http://127.0.0.1:8080/_panel/
🚀 Start serving requests at http://127.0.0.1:8080

In the future, we will start adding more features to it.

Development

Currently, the UI is shipped as a crate (panel) and integrated in the main project. The client uses React, Clarity Core and Vite. To develop this UI you need to install NodeJS and NPM in your environment.

Cargo automatically builds the UI based from the build.rs file. If npm is not available, the build pipeline will success, although the panel won't be available. We designed this way to avoid breaking build pipelines that don't relate to the client when node / npm is not available.

Integration

To integrate the compiled admin panel into the project, I used the rust-embed project. It automatically picks the files in a folder, embed them in the binary and provide an API to get the file content. With this approach we keep the server as a single-binary that it's easier to distribute.

It closes #153

[ereslibre]

LGTM, thanks @Angelmmiguel! A non-blocking minor question.

[assambar]

Looks great!