[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>

android/sdk/src/main/java/app/organicmaps/sdk/bookmarks/data/Metadata.java

@@ -70,7 +70,9 @@ public class Metadata implements Parcelable
     FMD_CONTACT_BLUESKY(51),
     FMD_PANORAMAX(52),
     FMD_CHECK_DATE(53),
-    FMD_CHECK_DATE_OPEN_HOURS(54);
+    FMD_CHECK_DATE_OPEN_HOURS(54),
+    //FMD_BRANCH(55),
+    FMD_CHARGE_SOCKETS(56);
     private final int mMetaType;
 
     MetadataType(int metadataType)