feat: split wws code in multiple crates

[Angelmmiguel]

The purpose of this PR is to split the current project into separate crates. Currently, all the code is split in modules inside the ./src folder. This is causing some issues:

• When importing wws as a library, it needs to compile the entire project. This includes clap and other libraries that are only related to the wws CLI
• Some parts of the code have cyclic dependencies (X relies on Y and the opposite). This is difficult to spot when all the code is in the same crate. By splitting it into multiple crates, we define a clear responsibility and API for the different crates
• Applying changes and fixes to specific crates is simpler to do it on the entire project
• We can use the Cargo workspace tooling to manage and share dependencies easily

Now it's a great moment to perfrom these changes as we just released a new version and we're planning to start using wws as a library.

For now, I identified these crates:

• config: manage the wws global configuration (.wws.toml file)
• data-kv: manage the KV in-memory store we ship with wws
• router: define the routes by loading files from the local filesystem. It also initializes the workers
• runtimes: initalize and configure wasmtime to run workers' source code.
• runtimes-manager: interacts with the remote repository to install and uninstall language runtimes (ruby, python, etc)
• server: run the final HTTP server users can query
• store: manage the temporary store for the runtime and worker files / folders
• worker: initialize all the required resources to run a worker from the given file. It also calls the runtime to return a response

It closes #102

[ereslibre]

Thanks @Angelmmiguel! It's awesome to see how this code evolves.

[ereslibre]

👏 🚢 it!