Revert "Workaround for GetQueryResultCountAsync not working as expected"

[dkbennett]

Summary of the pull request

This reverts commit 959bf8c.

The Azure fixes for the GetQueryResultCountAsync header have been deployed several weeks ago and should be widely available now. This reverts the fix so we can once again get accurate work item counts when the count is >25.

The referenced PR was never intended to be a permanent solution and was just to get widgets working again until the Azure fix was deployed and propagated to most/all environments.
 

References and relevant issues

Revert of #156

Detailed description of the pull request / Additional comments

Validation steps performed

• Built and deployed and tested Query List and Query Tiles with large work item count.
• Verified that the Tiles and List widget works as expected without errors.
• Verified the tile count is correct for large result queries (">25" is gone, replaced with actual count).

PR checklist

• Closes Undo workaround for GetQueryResultCountAsync not working as expected #179
• Tests added/passed
• Documentation updated