Revamp the marine DA verify task

[guillaumevernieres]

• [ ] readjust the way the plots are made (scatter size too large, field plots need to improve cosmetically, ... )
• [ ] It times out regularly, needs to be faster
• [ ] Add times series of obs count, bias, mae and rmse global and per ocean basin

[AndrewEichmann-NOAA]

• State space figures
  • [x] figures for bkg
  • [x] figures for currents
  • [x] different colorscales (finer scales for certain local intervals)
  • [x] contouring in slices
  • [ ] add sea ice figures (+ ice thickness and snow depth, ana and bkg)
  • [x] improve titles with everything (ana, bkg, inc, bkg err, etc.)
  • [ ] venture into tweaking eva plots (colorscale and x-axis scales)
• obs space
  • [x] ensmallen geographical scatterplot datapoints
  • [ ] obscounts on scatterplots and geographical plots
  • [ ] timeseries (mean abs error, rmse, bias)

[guillaumevernieres]

Example of color map for the bkg error: https://docs.google.com/presentation/d/1dmYs0GCh1EEZ_x3wGATQSvRZreqIyE8M1ipoQ_zWAYc/edit#slide=id.p