Improve CSET UI

[jfrost-mo]

The current CSET user interface (UI) has a number of issues. This ticket tracks efforts to resolve them.

UI Issues

• Move Select Plot so it doesn't overlap plot #795
• Information on welcome screen:
  Models and configurations run, case dates, recipes selected.
• Start on plot page
• View 4 plots at once.
• Postage stamp view for previewing many available plots.
• Disable description by default
• Additional information in description:
  More information for derived diagnostic. Input model / file that plot came from. Maybe even path to output files.
• The source model should be indicated in the produced plot #551
• Animate plot sequences #535
• Overlay/toggle between plots #302
• Interactive plots, e.g. toggling lines or extra info on click.
• Consistent Y axis length across line plots.
• Toggling with observations.
• Link sliders for side by side plots #552
• Plot title overlaps colorbar #815
• Transect information in title #811
• Case date information in menu item #932
• Postage stamp plot crowding of plot titles with many plots #368
• Order in menu isn't consistent.
• Select dropdown series might be easier to find corresponding plots. Dropdown can then be filled in any order.

Examples of visualisation UIs

• RES
• OVELAYS
• IMPROVER pages
• Dust monitoring pages
• ESMValTool output