Metadata defaults

[r-ash]

This PR will

• Set defaults to more closely match current prod, there are some deviations still but these are deliberate e.g. in the table. But let's review this with Jeff and Rachel and see if they want anything updated.
• Adds a new "value" into the PlotSetting this is where we want to a set a default value which is not the first from the dropdown. In particular useful in the bubble plot where having the colour and the size indicators set to the same thing isn't very useful.
• Hides the "detail" whenever "area" is a single-select. With both filters shown, it made these quite hard to use. If you changed a single select area, you would have to update the detail level to be lower than or equal to the area you had selected, which was a bit clumsy. Feels like a simpler UI to just select the area if it is a single select