NoMongo: Updating organisation model and queries

[MohitMaulekhi]

Is your feature request related to a problem? Please describe.
Revamping the organisation model and organisation queries and mutation according to the new schema.

Describe the solution you'd like
Changing the model to handle organisation.

Additional info
This issue fix will make user to join organisation.

Potential internship candidates

Please read this if you are planning to apply for a Palisadoes Foundation internship

• Student Internship Programs #359

[MohitMaulekhi]

@palisadoes pls assign.

[MohitMaulekhi]

If possible can i get the class model diagram or any other diagrams for the same.

[palisadoes]

All existing documentation can be found here:

• https://docs.talawa.io/

[MohitMaulekhi]

Thanks, pls assign for the issue

[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.

[MohitMaulekhi]

The backend and admin currently lacks some features. Waiting for these issues to get completed first

PalisadoesFoundation/talawa-api#3244, PalisadoesFoundation/talawa-api#3236, and PalisadoesFoundation/talawa-admin#3560