refactor(user): use single purpose token and auth to accept invite

[apoorvdixit88]

Type of Change

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

Description

• Use single purpose JWT auth and single purpose token for accept invite
• Remove user without merchant JWT auth and user auth token

Additional Changes

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

Motivation and Context

closes #4497

How did you test it?

• Enable email feature flag
• Signup/ singin
• Invite a new user from multiple accounts
• Sign in to newly created user
• The response should be merchant select, then do accept invite, it will give dashboard entry response.

Current and expected behaviour of accept invite should remain same!

curl --location 'http://localhost:8080/user/user/invite/accept' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer JWT' \
--data '{
    "merchant_ids": [
         "merchant_id1",
         "merchant_id2",
         "merchant_id3"
    ],
    "need_dashboard_entry_response": true
}'

If any of the merchant_id status is active, then you will be getting the following response.

{
    "token": "JWT with merchant_id, user_id, user_role",
    "merchant_id": "merchant_id",
    "name": "user name",
    "email": "user email",
    "verification_days_left": null,
    "user_role": "user role"
}

If need_dashboard_entry_response is false or not sent, then 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