Small cleanups to various data types. (#8086)

- Use `bst_bin_t` in batch param constructor.
- Use `StringView` to avoid `std::string` when appropriate.
- Avoid using `MetaInfo` in quantile constructor to limit the scope of parameter.

src/common/hist_util.cc

@@ -49,14 +49,14 @@ HistogramCuts SketchOnDMatrix(DMatrix *m, int32_t max_bins, int32_t n_threads, b
   }
 
   if (!use_sorted) {
-    HostSketchContainer container(max_bins, m->Info(), reduced, HostSketchContainer::UseGroup(info),
-                                  n_threads);
+    HostSketchContainer container(max_bins, m->Info().feature_types.ConstHostSpan(), reduced,
+                                  HostSketchContainer::UseGroup(info), n_threads);
     for (auto const& page : m->GetBatches<SparsePage>()) {
       container.PushRowPage(page, info, hessian);
     }
     container.MakeCuts(&out);
   } else {
-    SortedSketchContainer container{max_bins, m->Info(), reduced,
+    SortedSketchContainer container{max_bins, m->Info().feature_types.ConstHostSpan(), reduced,
                                     HostSketchContainer::UseGroup(info), n_threads};
     for (auto const& page : m->GetBatches<SortedCSCPage>()) {
       container.PushColPage(page, info, hessian);