Content and styling improvements

[sarahfossheim]

PR includes:

• Format numbers by locale
  Solves: Beta report formatting of large numbers and dates #865
• If API response is ALL, render the tech name as 'All Technologies' instead
  Solves: Rename "ALL" to "All technologies" #852
• Add technology description and categories in the drilldown view.
• Based on the selected color theme, choose a different set of colors from the settings in the line chart, to make sure it has enough contrast (3:1 or higher) against the background.
• Increase contrast of several other items to pass text and non-text contrast (navigation, dropdown icons on hover, tooltips).
• Bug: Dropdowns turn white while in focus (dark mode) #883
• Bug: Color theme doesn't get remembered on the landing page #882
• Tech report: Dropdowns z-index bug #904

[rviscomi]

Found during the meeting: the reports dropdown is behind the input fields, so moving the cursor over it closes the dropdown menu

[rviscomi]

Just a couple of minor suggestions

[rviscomi]

I see this is defined in a few places. In case we ever need to update the API host, could this be pulled up into a high-level constant?