Removed dummy plugins that are no longer relevant

Created by: stefanoborini

Removed the dummy plugins we used as a brainstorming activity, as we now have a concrete plugin that actually does data extraction.

examples/test_csv.json

 {
   "multi_criteria_optimizer": {
-    "name": "basic",
+    "name": "dakota",
     "model_data": {}
   },
   "data_sources": [