RFE: Improve trust event change notification in ADFSToolkit

[canariecaf]

Today ADFSToolkit uses the MSFT EventLog to record events and the regular operations.
Some events are more important than others however and when they happen, it would be extremely beneficial to have enhanced abilities to notify the site admin via different mediums of their occurence.

Notifications streams should be by event type and level and using existing best practices like syslog or eventlog streams and in turn, can in turn invoke a notification or report to anything associated with this stream. Anything with an API to communicate such as an email, messaging a Slack channel in realtime or sending an SMS to a gateway is able to be used.

For instance, augmenting ADFSToolkit with 3rd party components like this component for Slack can save effort: http://ramblingcookiemonster.github.io/PSSlack/ .
If ADFSToolkit does establish 3rd party dependancies we should be thoughtful on the integration elements we endorse and implement in such a way that is failure resistant as best possible to problems.

Some (not all) features of this event notification improvement RFE are:

• offer a way to enable this feature to be turned on in zero (back compatible mode) or more communication paths (e.g. get both email and slack channel updates)
• offer a way to have these settings in ADFSTkConfig files such that if they are NOT there, the feature would not result in a halt of the ADFSToolkit functionality and use the EventLog as it does now
• offer a way to aggregate information on the following models:
  • per run of a single configuration
    • e.g. notify this set of people for this aggregate, that set for another aggregate
  • per run of an entire synchronization of a set of configurations
    • e.g. after the sync has run, notify the of the events in their totality but per config only
• offer a way to either white list a set of zero or more entities for a different notification level
  • there may be a specific entity or set of entities that need elevated notifications
• offer a way to configure prefix/notification message format and content that is contained in an ADFSTKConfig or new ADFSTkLoggingConfig file to allow for site customization
  • this notification should permit ability to 'narrowcast' a notification specific at least to that event and maybe criteria (e.g. an entity has changed and a specifically attributes have changed
• offer a way to support email communication as a basic enhanced communication medium and perform a nonce requiring user admin to reply affirmatively to ensure communication stream is set up before being activated.
• alert the admin and get consent from admin that communications of this nature are exchanged over unsecured endpoints and subject to interception or reveals security configuration of the RPs for ADFS if used