Monitor Query readme and samples issues

[AFengKK]

Section link:

Reason:
TypeError: ABCMeta object got multiple values for keyword argument 'client_id'.

Suggestion:
Delete the code.

Section link:

Reason:
NameError: name 'timedelta' is not defined.

Suggestion:
Add the code from datetime import timedelta

@jameszliao-msft , @lmazuel , @scottaddie , @srnagar , @rakshith91 for notification.