Include dataset thumbnails on Explorer dataset pages

[robbibt]

Our new automatically generated products now have beautiful thumbnail JPEGs for each dataset that show at a glance what the data looks like, e.g. https://explorer-aws.dea.ga.gov.au/products/ga_ls8c_ard_3/datasets/558f9cef-91c7-402d-ac1d-10a4b69917bd https://data.dea.ga.gov.au/baseline/ga_ls8c_ard_3/107/079/2013/09/01/ga_ls8c_nbart_3-0-0_107079_2013-09-01_final_thumbnail.jpg

It would be fantastic to expose these images in Explorer, so that users can easy inspect a dataset without having to download it onto their PC. For example, this could look something like this, with the thumbnail displayed next to the map that shows where the data is located in Australia:

[robbibt]

An optional extra would be to perhaps re-arrange the dataset pages to bring the map and thumbnail up to the very top so it's the first thing users see, and move what I think is the product dependancy tree down further towards the bottom as it's a bit more niche info:

[robbibt]

Throwing further ideas out there... could the thumbnail be rendered on the map itself using Leaflet? 😱 That way users could zoom in and have a closer look if they wanted to check it out in more detail...

[robbibt]

Related issue: https://github.com/opendatacube/datacube-explorer/issues/297