feat(config): Add directional output selection via separate direction field

Add support for directional output selection in the move-to-output action
using a separate `direction` field instead of overloading OutputMatch.

API additions:
- Add Workspace::connector() to get the connector showing a workspace
- Add Connector::connector_in_direction() to find outputs directionally

Implementation:
- Move directional finding logic from toml-config to compositor
- Algorithm uses center-to-center distance with axis-aligned preference
- Add GetWorkspaceConnector and GetConnectorInDirection IPC messages

Configuration changes:
- Add optional `direction` field to move-to-output action
- Either `output` or `direction` must be specified (not both)
- Valid directions: "left", "right", "up", "down"

Example usage:
  logo+control+shift+right = { type = "move-to-output", direction = "right" }

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>

toml-config/src/config/extractor.rs

@@ -47,6 +47,10 @@ impl<'v> Extractor<'v> {
         self.log_unused = false;
     }
 
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
     pub fn extract<E: Extractable<'v>, U>(&mut self, e: E) -> Result<E::Output, Spanned<U>>
     where
         ExtractorError: Into<U>,