Feature: Add Managed Identity support

[abestel]

Pull Request Description

azure-kusto-java added support for Managed Identities from version 3.0.0. This commit adds support of managed identities in the Kusto Sink.

There are now two ways to authenticate against Azure Active Directory:

• using an Azure AD Enterprise Application
• using a Managed Identity

Both are service principals, the only different is that Managed Identity used the Azure Instance MetaData Service (IMDS) to get OAuth2 tokens, without the need to use a password.

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Future Release Comment

Breaking Changes:

• None

Features:

• Support managed identity to authenticate against ADX

Fixes:

• None

[ghost]

All CLA requirements met.

[abestel]

FYI: Putting this back to draft while I rebase on master.

[abestel]

@ohadbitt I did a second commit addressing your comments