Async Job Notification Service

[AllanOricil]

context: forcedotcom/salesforcedx-vscode#5445

Async sf/sfdx commands push the generated UUID to Async Job Notification Service (AJNS). Which can be installed through VS Code.
The post call must be wrapped with a try/catch because AJNS might not be running since not everyone uses VS Code. Moreover, it must have a very small timeout so that it does not hang for too long.

An alternative solution while Salesforce apis don't support configuring webhooks: #2068

[cristiand391]

closing this as I don't think the vscode folks are planning to work on this.