Add SplitsComponentState_column_label to C API

capi/src/splits_component_state.rs

@@ -128,3 +128,24 @@ pub extern "C" fn SplitsComponentState_is_current_split(
 ) -> bool {
     this.splits[index].is_current_split
 }
+
+/// Describes if the columns have labels that are meant to be shown. If this is
+/// `false`, no labels are supposed to be visualized.
+#[no_mangle]
+pub extern "C" fn SplitsComponentState_has_column_labels(this: &SplitsComponentState) -> bool {
+    this.column_labels.is_some()
+}
+
+/// Returns the label of the column specified. The list is specified from right
+/// to left. You may not provide an out of bounds index.
+#[no_mangle]
+pub extern "C" fn SplitsComponentState_column_label(
+    this: &SplitsComponentState,
+    index: usize,
+) -> *const c_char {
+    output_str(if let Some(labels) = &this.column_labels {
+        &labels[index]
+    } else {
+        ""
+    })
+}