6-Call-OwnApi-ManagedIdentity cannot work outside of Azure-hosted infra, and has confusing instructions

Hello there!

I just spent a couple of days working through this before realising that it was never going to work. Some issues, in no order:

- The readme says you need a VM or App Service running in Azure but doesn't tell you how to run the API server or the daemon in those environments
- **If you don't run the client in an Azure environment it cannot be given a managed identity.**
- If you run the client in an Azure environment, it's unlikely you'll be able to use `localhost` to reach the API server, so documentation on how to set that correctly would be helpful
- 'Expose an API' doesn't have a 'Set' button in the Azure Portal
- If you add the 'app role' verbatim in the manifest there's an error because `lang` is `null`. Removing it entirely works fine
- The instructions for granting the managed ID permissions on the app role could have inlined the relevant PowerShell from the linked documentation (and the changes required) - and made explicit that this operation is _not possible_ in the portal (unless I'm mistaken?)
- The docs don't say that you need to update the `Scopes` key in the console app config with the API server GUID
- As mentioned in #202 there are [spaces in some of the config keys](https://github.com/Azure-Samples/active-directory-dotnetcore-daemon-v2/blob/842a27175ec3d1d37fe193ae389257e17f0f6efc/6-Call-OwnApi-ManagedIdentity/daemon-console/appsettings.json#L8-L9), which breaks the parsing

Start with the README for 6-Call-OwnApi-ManagedIdentity and daemon-console/appsettings.json, including the linked configuration lines. Document how to run the API and daemon in Azure, configure the API endpoint and Scopes GUID, create the app role, and grant managed-identity permissions with the required PowerShell. Correct the config keys and verify the instructions against the sample flow.

Written by the indexing model from the issue text.