Update build-report.yml to handle release notification

[spbolton]

Currently build-report.yml is handling failure notifications from any of the workflow steps. In the case of release and also possibly other workflows based upon the new structure we may want to announce the successful completion of the workflow. We should include this messaging in this script that was previously in the Slack Notification step of maven-release-process-yml. As much as possible we should try to make this notification flexible and customizable with inputs on the script and not just focused on the one-release workflow, this can include passing in the slack channel to use and customizing the message sent, keeping consistent where it is possible.

e.g. success_message and success_channel could be optionally passed in, but success_message could default to a message based upon information of the current workflow, branch etc.

In the process also add the ability to pass in a channel to use for failure, and make sure we do not need to have multiple slack secrets if possible.