Add support for Microsoft Purview sensitivity labels for documents

[#1]

Description -
Add the ability to set Microsoft Purview sensitivity labels for documents from within Workfront.

Why is this feature important to you -
Our organization is requiring all documents within our agency to have a sensitivity level, and be able to set this within Workfront would save time. See more information about these sensitivity labels here:  https://learn.microsoft.com/en-us/purview/sensitivity-labels 

How would you like the feature to work -
Ideally we'd be able to set the sensitivity label of each document in the 'Documents' tab of a request or project. 

Current Behaviour -

This is not supported in Workfront.