Update Chat schema (GSOC)

[disha1202]

Is your feature request related to a problem? Please describe.
Update the Chat Schema

Describe the solution you'd like
Currently we have DirectChat and GroupChat, need to combine both in single Chat entity.

Describe alternatives you've considered

Approach to be followed (optional)

Additional context
Add any other context or screenshots about the feature request here.

Potential internship candidates
Please read this if you are planning to apply for a Palisadoes Foundation internship PalisadoesFoundation/talawa#359

[disha1202]

Please assign

[github-actions]

This issue did not get any activity in the past 10 days and will be closed in 180 days if no update occurs. Please check if the develop branch has fixed it and report again or close the issue.

[akshayw1]

Please assign

[Cioppolo14]

@akshayw1 If the issue has already been assigned, please don't ask to be assigned. We want everyone to get a chance

[github-actions]

This issue did not get any activity in the past 10 days and will be closed in 180 days if no update occurs. Please check if the develop branch has fixed it and report again or close the issue.

[nilaygit-10721]

Has this issue been resolved?