refactor(user_role): Remove V1 insertion for `user_roles` and allow Invites for `org_admins`

[ThisIsMani]

Type of Change

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

Description

Currently we are inserting user_roles in v1 version and v2 version. Since we have completely moved the APIs to support v2, we don't have to insert v1 anymore.

Allow inviting, updating and deleting org_admins.

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 #6184 Closes #6186

How did you test it?

All the following APIs will insert only v2 user_roles from now on.

curl --location 'https://integ-api.hyperswitch.io/user/signup' \
--header 'Content-Type: application/json' \
--data-raw '{
    "email": "new email",
    "password": "password"
}'

curl --location 'https://integ-api.hyperswitch.io/user/signup?token_only=true' \
--header 'Content-Type: application/json' \
--data '{
    "email": "new email",
    "password": "password"
}'

curl --location 'https://integ-api.hyperswitch.io/user/connect_account' \
--header 'Content-Type: application/json' \
--data-raw '{
    "email": "new email"
}'

curl --location 'https://integ-api.hyperswitch.io/user/internal_signup' \
--header 'api-key: test_admin' \
--header 'Content-Type: application/json' \
--data '{
    "name" : "name",
    "email" : "new email",
    "password": "password"
}'

curl --location 'https://integ-api.hyperswitch.io/user/user/invite_multiple' \
--header 'Content-Type: application/json' \
--data-raw '[
    {
        "email": "email",
        "name": "name",
        "role_id": "merchant_view_only"
    },
    {
        "email": "email 2",
        "name": "name",
        "role_id": "merchant_admin"
    }
]'

curl --location 'https://integ-api.hyperswitch.io/user/create_merchant' \
--header 'Content-Type: application/json' \
--header 'Authorization: ••••••' \
--data '{
    "company_name": "Juspay"
}'

You will now be able to invite org_admin

curl --location 'https://integ-api.hyperswitch.io/user/user/invite_multiple?token_only=true' \
--header 'Content-Type: application/json' \
--header 'Authorization: ••••••' \
--data-raw '[
    {
        "email": "email",
        "name": "name",
        "role_id": "org_admin"
    }
]'

Checklist

• [x] I formatted the code cargo +nightly fmt --all
• [x] I addressed lints thrown by cargo clippy
• [x] I reviewed the submitted code
• [ ] I added unit tests for my changes where possible