Added test case CG3

[Unknown31414652]

Description

Added test CG3 from design docs testing.md
Partly addresses #962

Type of change

• Note merging this changes the database configuration.
• This change requires a documentation update

Checklist

• I have followed the OED pull request ideas
• I have removed text in ( ) from the issue request
• You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

##Note
I am part of CodeDay doing this as a micro-internship with Shubham Waldiya

[huss]

@Unknown31414652 Did you do this work alone or with a team? If a team, could you let me know the team members to verify the CLA is signed by all of them. Thanks.

[huss]

Thanks to @Unknown31414652 for this pull request. Review and testing found it works as desired. It can be merged once my CLA comment is addressed.

[Unknown31414652]

My group member Shubham Waldiya signed the CLA

[huss]

Congratulations to @Unknown31414652 & @HiThere-12345 on your first accepted contribution to OED.