Adding webapp and webappPlan creation to deployment ARM template

[jainr]

• Adding support to create a linux app service plan
• Adding support to create an Azure webapp for containers that uses that plan and hosts a public dockerhub image
• Fixing a bug on instructions to fetch principalId, objectId is replaced by id property
  https://docs.microsoft.com/en-us/cli/azure/microsoft-graph-migration#breaking-changes

Successful deployment

Also adding instructions to create AAD app and to get clientId and TenantId.
Made corresponding changes in tempplate to accept them as parameters and pass it to webapp as settings.

[Yuqing-cat]

Shall we have a "provisionWebApp" parameter to let user decide whether to deploy it or not just like Purview & EventHub?

[xiaoyongzhu]

title says it's still WIP so not sure it's ready to take review or not?

But anyway I looked thru the changes and I'm good with those.

[jainr]

title says it's still WIP so not sure it's ready to take review or not?

But anyway I looked thru the changes and I'm good with those.

I had it work in progress, to update the final docker image that we deploy to UI app, currently it's a placeholder.

[xiaoyongzhu]

I looked thru the new experience, as above, a few feedbacks:

1. Docker Image - seems the description is wrong there. Also we should avoid using a specific person's name (like blchen)
2. Maybe rename "Docker Image" as "Pre-built Feathr UI Docker Image" or something like that so users know what we are talking about
3. We should probably combine the object ID and this AAD credential together since anyway they need to run thru the scripts

[jainr]

Thanks for the feedback @xiaoyongzhu, I will include that in subsequent PR