Remove dependency of "Microsoft.Azure.Management.Storage" from 4 module test.

## Description
Currently there are 4 modules test reference "Microsoft.Azure.Management.Storage" besides Az.Storage.
- src\ApplicationInsights\ApplicationInsights.Test\ApplicationInsights.Test.csproj
- src\EventGrid\EventGrid.Test\EventGrid.Test.csproj
- src\Synapse\Synapse.Test\Synapse.Test.csproj
- src\OperationalInsights\OperationalInsights.Test\OperationalInsights.Test.csproj

Other module (except Az.Storage) should not reference "Microsoft.Azure.Management.Storage", or we will have unnecessary dependency, and it will take trouble when Az.Storage upgrade "Microsoft.Azure.Management.Storage": other module test need upgrade or even re-record.

Please follow Az.Compute Test, to handle storage account management with ` \tools\ScenarioTest.ResourceManager\AzureRM.Storage.ps1`, and remove "Microsoft.Azure.Management.Storage" reference.

In the future, all new added module should not reference "Microsoft.Azure.Management.Storage".

## Cost
NA

Start with the four listed test project files and compare their storage-account handling with the Az.Compute Test approach. Read tools\ScenarioTest.ResourceManager\AzureRM.Storage.ps1, remove the Microsoft.Azure.Management.Storage references from the four projects, and verify that the tests use the shared script instead.

Written by the indexing model from the issue text.