[Feature: Autograding] Adds autograding example for database query gradeables

[shwehtom89]

This PR is a copy from the Submitty repo

Please check if the PR fulfills these requirements:

• The PR title and message follows our guidelines
• Tests for the changes have been added/updated (if possible)
• Documentation has been updated/added if relevant

What is the current behavior?

Currently there is no example for instructors to follow to create autograded database assignments in Docker.
There are no logging for database query metrics like (connection time, database ready time, query time)
This PR Is a continuation of #4649 which adds more logging for database assignments.

What is the new behavior?

• Adds example gradeable configuration.
• Provides a simple database example in Docker
• Adds example database 'client' for autograding
• Logs autograding database metrics (database ready time, query times)
  This file is stored in /var/local/submitty/courses/<semester>/<course>/results/<gradeableid>/<submitter>/<number>/details/<test number>/main/query_metrics.txt

Other information?

In order to build this gradeable, you need the example image.
Inside the vm run,
docker pull goofykubers/example_db_autograding:latest

Special Thanks for Prof Samuel B Johnson for providing a starting point for this PR.

[emaicus]

Tested, works.