Explore using BCGov's Tails Server Image

As highlighted in this issue, the way we are using Tails Server in our docker-compose file is currently using a custom image with a bunch of environment variables. We should investigate:

1. What, if any, of these environment variables are necessary.
2. Of the necessary environment variables, can we simplify the way their values are set at all
3. Can we use BCGov's Tails Server image instead: https://github.com/bcgov/indy-tails-server/pkgs/container/tails-server