Consider building an Azure Postgres client integration

[davidfowl]

We should simplify the life of developers using aspire if we built an azure postgres integration that supported postgres containers for local dev and managed identity based azure postgres when deployed.

We need to fix this for EF and the EF Npgsql client integrations.

See the instructions here:

https://learn.microsoft.com/en-us/dotnet/aspire/database/postgresql-integration?tabs=dotnet-cli#add-azure-authenticated-npgsql-client