## What changed?
<!-- Describe what has changed in this PR -->

Populate WorkflowExtendedInfo as a part of DescribeWorfklow response.

## Why?
<!-- Tell your future self why have you made these changes -->
Feature request. Users want to see workflow expiration time as a part of
DescribeWorfklow response.


## How did you test it?
<!-- How have you verified this change? Tested locally? Added a unit
test? Checked in staging env? -->
Update unit tests.

## Is hotfix candidate?
<!-- Is this PR a hotfix candidate or does it require a notification to
be sent to the broader community? (Yes/No) -->
No