[generator] retrieve socket:* OSM tags used by amenity:charging_station

Currently support the following socket types:
- type 1
- type 1 combo
- type 2 (wired or wo/ cable)
- type 2 combo
- chademo
- nacs

This commit also adds initial display of the socket types and power
the to Qt desktop app.

Signed-off-by: Séverin Lemaignan <severin@guakamole.org>

libs/indexer/map_object.cpp

@@ -178,6 +178,57 @@ std::string_view MapObject::GetOpeningHours() const
   return m_metadata.Get(MetadataID::FMD_OPEN_HOURS);
 }
 
+ChargeSocketDescriptors MapObject::GetChargeSockets() const
+{
+  ChargeSocketDescriptors sockets;
+
+  auto s = std::string(m_metadata.Get(MetadataID::FMD_CHARGE_SOCKETS));
+  if (s.empty())
+    return sockets;
+
+  auto tokens = strings::Tokenize(s, ";");
+
+  for (auto token : tokens)
+  {
+    if (token.empty())
+      continue;
+
+    auto fields = strings::Tokenize(token, "|");
+
+    if (fields.size() < 3)
+      continue;  // invalid entry, skip
+
+    ChargeSocketDescriptor desc;
+    desc.type = fields[0];
+
+    try
+    {
+      desc.count = std::stoi(std::string(fields[1]));
+    }
+    catch (...)
+    {
+      desc.count = 0;
+    }
+
+    if (fields.size() >= 3)
+    {
+      try
+      {
+        desc.power = std::stod(std::string(fields[2]));
+      }
+      catch (...)
+      {
+        desc.power = 0;
+      }
+    }
+    else
+      desc.power = 0;
+
+    sockets.push_back(desc);
+  }
+  return sockets;
+}
+
 feature::Internet MapObject::GetInternet() const
 {
   return feature::InternetFromString(m_metadata.Get(MetadataID::FMD_INTERNET));
@@ -242,6 +293,11 @@ int MapObject::GetStars() const
   return count;
 }
 
+std::string MapObject::GetCapacity() const
+{
+  return std::string(m_metadata.Get(MetadataID::FMD_CAPACITY));
+}
+
 bool MapObject::IsPointType() const
 {
   return m_geomType == feature::GeomType::Point;