feat: replace chb with consent groups and preserve runtime config (api#317, #17)

config.json

@@ -39,12 +39,12 @@
       },
       "default": "a"
     },
-    "chb": {
+    "cons": {
       "weights": {
-        "a": 1,
-        "b": 0
+        "1": 100,
+        "2": 0
       },
-      "default": "b"
+      "default": "2"
     },
     "tp": {
       "weights": {