New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/indexer/feature_source.cpp

@@ -0,0 +1,54 @@
+#include "indexer/feature_source.hpp"
+
+std::string ToString(FeatureStatus fs)
+{
+  switch (fs)
+  {
+  case FeatureStatus::Untouched: return "Untouched";
+  case FeatureStatus::Deleted: return "Deleted";
+  case FeatureStatus::Obsolete: return "Obsolete";
+  case FeatureStatus::Modified: return "Modified";
+  case FeatureStatus::Created: return "Created";
+  };
+  return "Undefined";
+}
+
+FeatureSource::FeatureSource(MwmSet::MwmHandle const & handle) : m_handle(handle)
+{
+  if (!m_handle.IsAlive())
+    return;
+
+  auto const & value = *m_handle.GetValue();
+  m_vector = std::make_unique<FeaturesVector>(value.m_cont, value.GetHeader(), value.m_table.get(),
+                                              value.m_metaDeserializer.get());
+}
+
+size_t FeatureSource::GetNumFeatures() const
+{
+  if (!m_handle.IsAlive())
+    return 0;
+
+  ASSERT(m_vector, ());
+  return m_vector->GetNumFeatures();
+}
+
+std::unique_ptr<FeatureType> FeatureSource::GetOriginalFeature(uint32_t index) const
+{
+  ASSERT(m_handle.IsAlive(), ());
+  ASSERT(m_vector, ());
+  auto ft = m_vector->GetByIndex(index);
+  ft->SetID({ GetMwmId(), index });
+  return ft;
+}
+
+FeatureStatus FeatureSource::GetFeatureStatus(uint32_t index) const
+{
+  return FeatureStatus::Untouched;
+}
+
+std::unique_ptr<FeatureType> FeatureSource::GetModifiedFeature(uint32_t index) const { return {}; }
+
+void FeatureSource::ForEachAdditionalFeature(m2::RectD const & rect, int scale,
+                                             std::function<void(uint32_t)> const & fn) const
+{
+}