Batch details improvements

[mhauru]

Various improvements to batch_list and batch_details:

• Remove unnecessary columns
• Show the T&RH plots in batch_details already before harvest
• Add placeholders for said plots when they are not made, i.e. before the batch is transferred to the main farm
• Add mean T&RH information for the propagation period to batch_details
• Report yield per square metre rather than yield per tray
• Add a button to download the data of the T&RH plots in batch_details
• Also, unrelatedly, sort downloaded data in the timeseries dashboard by timestamp, as requested by Zack.

Closes https://github.com/alan-turing-institute/CROP/issues/345, https://github.com/alan-turing-institute/CROP/issues/332, https://github.com/alan-turing-institute/CROP/issues/347, https://github.com/alan-turing-institute/CROP/issues/346, https://github.com/alan-turing-institute/CROP/issues/341