Sequence Manager: report sequencing failures to #biobots channel

[reisingerf]

Sequencing failures are generally not recoverable, so any failures or errors should be flagged asap for end users (i.e. the #biobots Slack channel). This should be based on the Sequence Managers internal state handling, e.g. focus on sequencing events and not BSSH analysis events (i.e. events before PendingAnalysis)

[raylrui]

PR #886 merged.

When deployed to prod, I will add this resource policy to the SNS topic to allow orcabus to send events to this topic.

{
      "Sid": "AWSEvents_OrcaBusProd-SequenceRunManagerStackSlackNotificationRule_Id85755e27-3dd5-408e-9091-9cbc7315db7e", // uuid will be new generated
      "Effect": "Allow",
      "Principal": {
        "Service": "events.amazonaws.com"
      },
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:ap-southeast-2:843407916570:AwsChatBotTopic-alerts"
 }