Keep only one code for metrics in cross-validation

See merge request !223

Merge branch 'dev-Scorecards_improvements' of https://earth.bsc.es/gitlab/es/sunset into dev-Scorecards_improvements

# Conflicts:
#   modules/Scorecards/R/tmp/ScorecardsMulti.R

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

Crossval_calibration to use Apply

See merge request !219

Fix recipe call to custom dictionary

See merge request !221

Add Crossval_multimodel_metrics.R

See merge request !220

Read fcst sdate when saving metrics for subseasonal case; improve .get_times()

See merge request !218

Update RandomWalkTest.R

See merge request !216

Update versions of RPS() and RPSS() to s2dv master

See merge request !214

Units module to work for the case of 'tos' in degC

See merge request !215

Add Ethiopia and update EU for BigPrediData

See merge request !213

Fix Scorecards Multimetric

See merge request !211

Remove January 1993 start date for UKMO

See merge request !144