Add EXER-007 requirements

Change description

Changes:

• Added a Kotlin program that connects to PostgreSQL
• Added a function to execute EXER-002 query
• Added a query to get org_id, agreement_id and signatory_count
• Added a loop to compute the average number via Kotlin
• Separated data class and methods from main
• Revised file names, class name.
• Initialized project files

Type of change

• Bug fix (fixes an issue)
• New feature (adds functionality)

Related issues

Fix #1

Checklists

Development

• Lint rules pass locally
• Application changes have been tested thoroughly
• Automated tests covering modified code pass

Security

• Security impact of change has been considered
• Code follows company security practices and guidelines

Network

• Changes to network configurations have been reviewed
• Any newly exposed public endpoints or data have gone through security review

Code review

• Pull request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached as necessary
• "Ready for review" label attached and reviewers assigned
• Changes have been reviewed by at least one other contributor
• Pull request linked to task tracker where applicable