Rebase eShopOnDapr on MSLearn microservices app

[amolenk]

Instead of extensively cleaning up the current eShopOnDapr implementation (which is based on the dev branch of eShopOnContainers), we can use the MSLearn microservices sample as the foundation.

Subtask	Status
Docker Compose	✅ #1
Secret store	✅ #3 / #4
State store (Basket)	✅ #3 / #4
Pub/sub	✅ #6
Service invocation	✅ #5
Observability	✅ #5

[amolenk]

Merged #1 as the sample is now up and running with Dapr containers in Docker Compose. Still need to migrate the code that actually uses Dapr, will create another PR for that.

BTW @nishanil I really like the new UI, looks much more modern