[Backend] Basic user endpoints added

[singhayushh]

Fixes #101

Changes done

• [x] Following endpoints have been added:
  • register as customer or staff
  • login as customer or staff
  • fetch all customers
  • fetch all staff
  • fetch user by id or by email or by phone number
• [x] Swagger has been added for API documentation.
  • A separate /docs route has been created where all API descriptions are available along with success response body.

Screenshots of the changes (If any) -

User Registration - other routes have been tested as well

API Documentation - as seen under /docs route

Note: Please check Allow edits from maintainers. if you would like us to assist in the PR.

✅️ By submitting this PR, I have verified the following

• [x] Worked on forked repo and starred the main repo
• [x] Checked to see if a similar PR has already been opened 🤔️
• [x] Reviewed the contributing guidelines 🔍️
• [x] Sample preview link added (add the link(s) for all the pages changed/updated from the checks tab after checks complete)
• [ ] Tried Squashing the commits into one

[singhayushh]

1. employee can't be created using same phone or email

@ayan-biswas0412 yes, I have added a check for that. Line 17 -> for customers and line 31 -> for employees in controller/user.controller.js

[singhayushh]

@singhayushh I will merge your PR with first priority , please resolve the thing I have commented and ask for a review I will merge it

To make sure that no user registers as employee or customer with same phone number or email twice, I have set the email and phone number key to be unique in the mongo schema as well as provided a check whether the email or phone number exists in the database under the registering controller. I hope the raised issue is resolved.

For the check that is failing, variables from request body are needed for verifying the password and logging in the user. I have no clue why the check fails for using variables passed by the user.

[aniketsingh98571]

@singhayushh You can check at the particular checks by clicking on details link it will show you where your checks are failing, please look into it....

[singhayushh]

@aniketsingh98571 Yes I did that. Only after checking the details, I came to know that the checking is failing because I'm using parameters that the user will pass.

And not knowing why such a check causes failure, I commented the above.

[aniketsingh98571]

@singhayushh you can check on StackOverflow for the issue.

[singhayushh]

@aniketsingh98571 All checks have passed. I hope the PR is all good now.