Add extended properties to recommendation model

[parkhyukjun89]

Add extended properties that expose additional information about a recommendation from Advisor.

This checklist is used to make sure that common issues in a pull request are addressed. This will expedite the process of getting your pull request merged and avoid extra work on your part to fix issues discovered during the review process.

PR information

• The title of the PR 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 information on cleaning up the commits in your pull request, see this page.
• Except for special cases involving multiple contributors, the PR is started from a fork of the main repository, not a branch.
• If applicable, the PR references the bug/issue that it fixes.
• Swagger files are correctly named (e.g. the api-version in the path should match the api-version in the spec).

Quality of Swagger

• I have read the contribution guidelines.
• My spec meets the review criteria:
  • The spec conforms to the Swagger 2.0 specification.
  • The spec follows the guidelines described in the Swagger checklist document.
  • Validation tools were run on swagger spec(s) and have all been fixed in this PR.

[AutorestCI]

Automation for azure-sdk-for-python

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-python#2843

[AutorestCI]

Automation for azure-sdk-for-ruby

Nothing to generate for azure-sdk-for-ruby

[AutorestCI]

Automation for azure-sdk-for-node

Encountered a Subprocess error: (azure-sdk-for-node)

Command: ['/usr/local/bin/autorest', '/tmp/tmp0jnmeubd/rest/specification/advisor/resource-manager/readme.md', '--license-header=MICROSOFT_MIT_NO_VERSION', '--node-sdks-folder=/tmp/tmp0jnmeubd/sdk', '--nodejs', '--use=@microsoft.azure/autorest.nodejs@^2.1.43']
Finished with return code 1
and output:

AutoRest code generation utility [version: 2.0.4283; node: v8.11.3]
(C) 2018 Microsoft Corporation.
https://aka.ms/autorest
   Loading AutoRest core      '/root/.autorest/@microsoft.azure_autorest-core@2.0.4283/node_modules/@microsoft.azure/autorest-core/dist' (2.0.4283)
   Loading AutoRest extension '@microsoft.azure/autorest.nodejs' (^2.1.43->2.1.79)
   Loading AutoRest extension '@microsoft.azure/autorest.modeler' (2.3.44->2.3.44)
FATAL: System.Exception: Duplicate File Generation: lib/models/configurationListResult.js
   at AutoRest.Core.CodeGenerator.<Write>d__13.MoveNext() in /opt/vsts/work/1/s/autorest.common/src/CodeGenerator.cs:line 151
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at AutoRest.Core.CodeGenerator.<Write>d__12.MoveNext() in /opt/vsts/work/1/s/autorest.common/src/CodeGenerator.cs:line 121
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at AutoRest.NodeJS.Azure.CodeGeneratorJsa.<Generate>d__5.MoveNext() in /opt/vsts/work/1/s/src/azure/CodeGeneratorJsa.cs:line 56
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at AutoRest.NodeJS.Program.<ProcessInternal>d__3.MoveNext() in /opt/vsts/work/1/s/src/Program.cs:line 132
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at NewPlugin.<Process>d__20.MoveNext() in /opt/vsts/work/1/s/autorest.common/src/Plugins/NewPlugin.cs:line 163
FATAL: nodejs/generate - FAILED
FATAL: Error: Plugin nodejs reported failure.
Process() cancelled due to exception : Plugin nodejs reported failure.
  Error: Plugin nodejs reported failure.

[AutorestCI]

Automation for azure-sdk-for-java

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-java#2299

[AutorestCI]

Automation for azure-sdk-for-go

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-go#2400

[sergey-shandar]

@ravbhatnagar Changes in the stable API.

[sergey-shandar]

@ravbhatnagar we also need ARM approval for the changes.

[azuresdkci]

Can one of the admins verify this patch?

[ravbhatnagar]

This should not be a breaking change. /recommendations does not have a PUT API. So even if the older SDKs ignore the extra properties coming back, it should not result in a breaking change.