Change setup validation to use a dto

[Hinton]

Type of change

• Bug fix
• New feature development
• Tech debt (refactoring, code cleanup, dependency upgrades, etc)
• Build/deploy pipeline (DevOps)
• Other

Objective

Changes the setup application to use a DTO for the response from the bitwarden server. This ensures we use the System.Text.Json Web defaults https://docs.microsoft.com/en-us/dotnet/api/system.text.json.jsonserializerdefaults?view=net-6.0#system-text-json-jsonserializerdefaults-web which are case-insensitive. It's also nicer than using JsonDocument.

Testing requirements

Verify setup works against prod. (Would be nice to verify it correctly checks Disabled)

Before you submit

• I have checked for formatting errors (dotnet tool run dotnet-format --check) (required)
• If making database changes - I have also updated Entity Framework queries and/or migrations
• I have added unit tests where it makes sense to do so (encouraged but not required)
• This change requires a documentation update (notify the documentation team)
• This change has particular deployment requirements (notify the DevOps team)

[justindbaur]

Love it!