This allows using up and start with uv:

## How to use:

```bash
cd examples/python-dataflow
dora up
dora start dataflow.yaml --uv
```

Fixes: https://github.com/dora-rs/dora/issues/780

This would help the CI as well

We use `/` as separator for input mappings in dataflow YAML files (e.g. input: `node/output_id`).

We do support `/` characters in output IDs for runtime nodes. If we allowed `/` characters in node IDs too, splitting a `a/b/c` mapping would no longer be possible (could be node `a` with output `b/c` or node `a/b` with output `c`). Therefore we explicitly error on node IDs containing `/` characters in this commit.

Send an exit message from the daemon to the coordinator on exit. This enables the coordinator to disconnect the daemon properly instead of waiting for a missed heartbeat signal.

This can be useful for debugging

The previous machine ID is still used, but optional. Users don't need to ensure that the chosen machine IDs are unique anymore because they are augmented with a UUID.

To ensure forward compatiblity

Ensures that we need to update `dora-message` less often.

Make `dora-message` a dependency of `dora-core`, instead of the other way around. This way, we can continue to freely bump the version of `dora-core` with the other workspace crates, without introducing errors such as #708.

First step towards versioning the message definitions indepedently.

* Remove automatic `capnp build` of messages ser/de

Removing Capnproto default build removes the risk of compilation errors due to missing capnproto dependencies and removes a step in the installation of dora.

Ultimately if someone wants to update the capnproto schema, he/she will build the script once.

* Changing capnp build output to src to be commited

* Add documentation of disabled build