Keep record of past imagebuilding options

[yuvipanda]

When using imagebuilding, we don't want the user to have to keep typing in their repo / ref each time. We should find some way of keeping a persistent list of previous things they have typed in, so they can simply 'select' those and keep going.

[oliverroick]

If we want to do this in the client, here’s how I think this can work:

• We store previously used repository/ref combinations in an IndexedDB table
• Each record will have three fields
  • repository
  • ref
  • last_used
• When the user starts an image build, we add the repository and ref the to the table, or update the record if the combination already exists
• We extend the textfields for repository and ref to a use the Combobox: Users start typing a value into the field and we present them with a list of options previously used.
• We can limit the values in the list to those used recently; for example, in the last 30 days
• To keep the memory footprint of IndexedDB small, we can run clean-ups jobs when the page is loading, to remove any values older than 30 days from the table