Aggregate old plugins under the "dummy" core plugin

Created by: stefanoborini

We move the old plugins in the single "dummy" plugin, so we have only one.

doc/source/api/force_bdss.core_plugins.dummy.csv_extractor.rst

-force_bdss.core_plugins.dummy_kpi.kpi_adder package
+force_bdss.core_plugins.dummy.csv_extractor package
 ===================================================
 
 Submodules
 ----------
 
-force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_bundle module
--------------------------------------------------------------------
+force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_bundle module
+-----------------------------------------------------------------------
 
-.. automodule:: force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_bundle
+.. automodule:: force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_bundle
     :members:
     :undoc-members:
     :show-inheritance:
 
-force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_calculator module
------------------------------------------------------------------------
+force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_data_source module
+----------------------------------------------------------------------------
 
-.. automodule:: force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_calculator
+.. automodule:: force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_data_source
     :members:
     :undoc-members:
     :show-inheritance:
 
-force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_model module
-------------------------------------------------------------------
+force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_model module
+----------------------------------------------------------------------
 
-.. automodule:: force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_model
+.. automodule:: force_bdss.core_plugins.dummy.csv_extractor.csv_extractor_model
     :members:
     :undoc-members:
     :show-inheritance:
@@ -32,7 +32,7 @@ force_bdss.core_plugins.dummy_kpi.kpi_adder.kpi_adder_model module
 Module contents
 ---------------
 
-.. automodule:: force_bdss.core_plugins.dummy_kpi.kpi_adder
+.. automodule:: force_bdss.core_plugins.dummy.csv_extractor
     :members:
     :undoc-members:
     :show-inheritance: