Add lamp technology type to metrics (led / halogen / ...)

Backfills type for L0001-L0011 (led) and L0012 (halogen); new
measurements record it via lamp_station.py.

lamps/L0012/metrics.json

@@ -1,6 +1,7 @@
 {
   "name": "L0012",
   "ean": "4008321211828",
+  "type": "halogen",
   "rated": {
     "Power_W": 28,
     "lifetime_h": 2000,