WIP: load oranda.toml as well

[Gankra]

Notes:

• is currently hacky because of the way oranda selects oranda.json
  • if the config path doesn't exist, but it ends with .json, tries .toml as well
  • because at that point in the code we can't distinguish user-provided path and the default path
• analytics needs to be written in a kind of messed up way because of Deserialize enum table? toml-rs/toml-rs#390
• this PR replaces oranda.json with oranda.toml just to show it off, but that breaks web.yml and obviously shouldn't be merged