Support multiple VGSs

[mjennings061]

As an admin, I want to support multiple gliding units, so that the dashboard can be used by more people

Dev notes

• [x] Research methods of adding multiple DB credentials
• [x] Add unit selection when authenticating
• [x] Add 626 VGS credentials to test
• [x] Test on streamlit
• [ ] STRETCH: Add a logout. Delete the cookie when logging out

[mjennings061]

• [x] Add an auth project
• [x] Add an auth database to auth project
• [x] Add users collection
• [x] Add "allowed_vgs" field with the allowed VGSs e.g. ["626vgs", "661vgs"]
• [x] Add vgs_db collection with details of each VGS DB into the auth database in the same format of db_hostname etc.
• [x] Change streamlit secret to contain only the auth project and auth db details
• [x] Add VGS drop down and password box
• [x] Refactor get_config to grab the launches collection using the URL grabbed from the auth collection
• [x] Add issue to make update-logs work with:
  • auth database hostname
  • select vgs
  • hard code the other DB details for the auth database