Use Start() in LoadMetrics(); modify Scorecards plotting functions accordingly, save significance in Scorecards_calculations()

Change get_timeidx() name to get_forecast_times() and add unit test

See merge request !208

Crossval_anomalies fix for fcst null case

See merge request !210

Review seasonal and reference archive for gpfs to produce scorecards

See merge request !209

Add script to compute Anomalies in full cross-validation

See merge request !204

Load observation data from calculated dates instead of using hindcast metadata

See merge request !202

Always request one node with Autosubmit + Update use case

See merge request !206

Update VizEquiMap.R to esviz version

See merge request !205