More support for column split in cpu predictor (#9244)

- Added column split support to `PredictInstance` and `PredictLeaf`.
- Refactoring of tests.

src/predictor/gpu_predictor.cu

@@ -929,7 +929,7 @@ class GPUPredictor : public xgboost::Predictor {
 
   void PredictInstance(const SparsePage::Inst&,
                        std::vector<bst_float>*,
-                       const gbm::GBTreeModel&, unsigned) const override {
+                       const gbm::GBTreeModel&, unsigned, bool) const override {
     LOG(FATAL) << "[Internal error]: " << __func__
                << " is not implemented in GPU Predictor.";
   }