[Feature] ServiceNow open incident polling

## Feature description

Allow ServiceNow incident handler to poll open tickets currently assigned to itself to check for updated information. Currently the Agent does not have the ability to see updated information in the work or customer notes to continue with the investigation.

Message from the Agent itself when asking it to pull updated ticket information:

> Blocked: the current ServiceNow capability cannot list/read incidents or customer comments. It only supports posting or updating known incidents.

## Use case

A customer submits a ticket which the Agent picks up. The Agent works the ticket, but needs additional information. The additional information gets added in the incident ticket itself and the Agent continues its investigation.

## Current workaround

The Agent administrator/user has append the information to the incident chat for the investigation to continue.

## Proposed approach

Give the Agent the proper tools to read through work notes that have been added.

Start with the ServiceNow incident handler and its existing incident tools. Trace how assigned incidents are identified and how work or customer notes are exchanged; done means the Agent can poll its open assigned incidents and read newly added notes so the investigation can continue.

Written by the indexing model from the issue text.