Use separate version for `dora-message` crate

Decouples the `dora-message` version from the version of the other `dora-*` crates. This allows us to use semver-versioning for the `dora-message` crate to encode message compatibility across dora versions.

Cargo.toml

@@ -66,6 +66,7 @@ dora-coordinator = { version = "0.3.5", path = "binaries/coordinator" }
 dora-ros2-bridge = { path = "libraries/extensions/ros2-bridge" }
 dora-ros2-bridge-msg-gen = { path = "libraries/extensions/ros2-bridge/msg-gen" }
 dora-ros2-bridge-python = { path = "libraries/extensions/ros2-bridge/python" }
+# versioned independently from the other dora crates
 dora-message = { version = "0.3.5", path = "libraries/message" }
 arrow = { version = "52" }
 arrow-schema = { version = "52" }

libraries/message/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "dora-message"
-version.workspace = true
+# versioned separately from the other dora crates
+version = "0.3.5"
 edition = "2021"
 documentation.workspace = true
 description.workspace = true