Simplify TS numbers draws : resize mingen TS when hydro TS are generated

Behavior before this commit :
   When hydro TS are generated, mingen are not generated : it is sized with 1 column.
   So (given an area and a year) a TS number for ror and storage does not apply to mingen in this case.
   It causes extra complexity in class TimeSeries to handle this.
   Note that, still in this case (hydro TS are generated), the only mingen TS is filled with zeros.

Behavior after this commit :
   We remove the complexity in class TimeSeries by doing the following :
   If hydro TS are generated, mingen TS matrix is resized to the number of TS to be generated and filled with zeros.
   So we still have a mingen of zeros.

src/libs/antares/study/parts/hydro/series.cpp

@@ -236,10 +236,11 @@ void DataSeriesHydro::reset()
     count = 1;
 }
 
-void DataSeriesHydro::resizeRORandSTORAGE(unsigned int width)
+void DataSeriesHydro::resetGenerationTS(unsigned int width)
 {
-    ror.resize(width, HOURS_PER_YEAR);
-    storage.resize(width, DAYS_PER_YEAR);
+    ror.reset(width, HOURS_PER_YEAR);
+    storage.reset(width, DAYS_PER_YEAR);
+    mingen.reset(width, HOURS_PER_YEAR);
     count = width;
 }
 

src/libs/antares/study/parts/hydro/series.h

@@ -58,7 +58,7 @@ class DataSeriesHydro
     */
     void reset();
 
-    void resizeRORandSTORAGE(unsigned int width);
+    void resetGenerationTS(unsigned int width);
     void resizeGenerationTS(unsigned int w, unsigned int h);
 
     /*!

src/solver/ts-generator/generator.hxx

@@ -59,7 +59,7 @@ inline void ResizeGeneratedTimeSeries(Data::AreaList& areas, Data::Parameters& p
         // Hydro
         if (params.timeSeriesToRefresh & Data::timeSeriesHydro)
         {
-            area.hydro.series->resizeRORandSTORAGE(params.nbTimeSeriesHydro);
+            area.hydro.series->resetGenerationTS(params.nbTimeSeriesHydro);
         }
 
         // Thermal