YARN-10422: add python script for collecting diagnostic data

[Hean-Chhinling]

Description of PR

Upon agree, the application_failed & application hanging combines into "Application Diagnostic". This endpoint will be called by YARN UI2.

The scheduler_related_issue endpoint will be called by the new YARN QueueManager UI for capacity scheduler.

The RM_NM_startup failures have been removed as it is not feasible to implement a UI for it in real case scenario.

How was this patch tested?

Manually, and will write a unit-test for it.

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?
• Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?