feat(users): Add preferred_merchant_id column and update user details API

[ThisIsMani]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

• This PR adds a new column in users table called preferred_merchant_id. preferred_merchant_id will be used at the time of signin to directly use that merchant_id when user has access to multiple merchant accounts.
• This PR adds a new API which enables users to update their name and preferred merchant id.

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

To support the highlighted flow in the following diagram.
Note: This PR doesn't have the actual changes of the flow, but has few required changes to make the highlighted flow possible.

flowchart TD
    A["Connect Account"] -- Email --> B{"User Exists"}
    B -- No --> C["Create new \n Org \n Merchant \n User \n User Role"]
    C --> D["Send Verify Email"]
    D --> E["Verify Email Token"]
    B -- Yes --> D
    E --> H{"Is there\n any perferred \nmerchant"}
    F -- ==0 --> I{{"Send list of \nmerchants which\n user has access to\n along with an\n intermediate token"}}
    F -- >1 --> G[Select the first role with active status]
    subgraph Preferred Merchant
	    H -- Yes --> M["Send the token \nwith that merchant_id"]
    end
    H -- No --> F{"How many \n active merchants\n does user have \naccess to"}
    I -- merchant_ids, \nintermediate_token --> O["Accept Invite"]
    O --> P["Change status to active"]
    P --> G
    G --> M
    K["Sign In"] -- Email, Password --> H

Loading

How did you test it?

Postman.

curl --location 'http://localhost:8080/user/update' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer JWT' \
--data '{
    "name": "user name", // Optional
    "preferred_merchant_id": "merchant_id" // Optional, user should have access to this merchant_id
}'

If the api is successful, the db will be updated and the response will be 200 OK.

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible
• I added a CHANGELOG entry if applicable

[apoorvdixit88]

LGTM

[racnan]

Minor thing other than that LGTM.