[RFE] Notification/Alert to be generated upon Task completion with task completion status

[julienlim]

As a Tendrl Admin / Normal User, I expect to see notifications/alerts whenever a task I triggered has completed, e.g. Import Cluster. The notification/alert should include the task, task ID, and task completion status (e.g. import failed, completed successfully).

Related reference:

• Import Task Submitted - typo and maybe rewording needed; no notification after import task completes ui#550 (comment)

@Tendrl/tendrl-core