[HDInsight] Fixed applications and MSI, added application test

[wawon-msft]

Description

Regenerating from Swaggers with changes in this PR: Azure/azure-rest-api-specs#4364

This change is technically a breaking change, as we are removing a parameter. However, there should be no users affected, as this method would always have thrown an error from the SDK. Additionally, a new test has been added to verify that this call works properly.

There is a minor fix to customization related to MSI, where a property in a custom data model was private when it should have been public.

---

This checklist is used to make sure that common guidelines for a pull request are followed.

• Please add REST spec PR link to the SDK PR
• I have read the contribution guidelines.
• The pull request does not introduce breaking changes.

General Guidelines

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

SDK Generation Guidelines

• If an SDK is being regenerated based on a new swagger spec, a link to the pull request containing these swagger spec changes has been included above.
• The generate.cmd file for the SDK has been updated with the version of AutoRest, as well as the commitid of your swagger spec or link to the swagger spec, used to generate the code.
• The *.csproj and AssemblyInfo.cs files have been updated with the new version of the SDK.

[dsgouda]

LGTM

[dsgouda]

Will merge on CIs passing