Switch dashboard to nginx and add caching for the /dashboard/homePageStats

[ansell]

The URL https://dashboard.ala.org.au/dashboard/homePageStats is called by visitors to the front page, https://www.ala.org.au/ to update the default counts. It would be ideal if this URL were cached by nginx and users browsers for a small amount of time to minimise the number of times that query needs to go to the dashboard app.

The current dashboard.ala.org.au server uses apache, so this support could be added on the next iteration when it is moved to a different server.