This commit does not implement event logging yet.

Update to Rust v1.70

Remove deprecated `proc_macros` feature from `safer-ffi` dependency

Don't recompile the `dora-operator-api-c` crate on every build/run

The `proc-macro` feature is now a built-in.

By default, cargo reruns build scripts whenever any file of the package changes. This led to lots of unnecessary rebuilds of the `dora-operator-api-c` crate. The reason is that crate has a build script that updates the `operator_types.h` file, which is considered as a modification by cargo. So it reruns the build script on the next `cargo build` or `cargo run` command, which leads to subsequent rebuilds of all crates that depend on `dora-operator-api-c`.

This commit fixes this issue by instructing cargo to never rerun the build script (through a special `println`). This way the package is considered 'fresh' on rebuilds. Cargo will still rerun the build script when the `dora_operator_api_types` crate changes, so the `operator_types.h` file still stays up-to-date.

Add timestamps generated by hybrid logical clocks to all sent events

Make dataflow descriptor available to Python nodes and operators

Return dataflow result to CLI on `dora stop`

The `with_extension` method returns a new path, it does not modify the existing path.

The dataflow might be finished already when `dora stop` is invoked, which caused an error previously. This commit changes this behavior to return the dataflow result instead in this case.

Release v0.2.3 with aarch64 support

The name generator uses a thread-local random number generator internally, which makes it `!Send`. So we should not keep it across await points because our `multiple_daemons` example needs to spawn it in the tokio runtime, which requires `Send`.