feat(users): Convert emails to lowercase from requests

[ThisIsMani]

Type of Change

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

Description

This PR changes will convert emails from request to lowercase before performing any DB operations.

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 #6600.

How did you test it?

curl --location 'http://localhost:8080/user/connect_account' \
--header 'Content-Type: application/json' \
--data-raw '{
    "email": "[email protected]"
}'

This email in the about request will be inserted as [email protected] in DB.

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

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
crates/router/src/types/domain/user.rs	18% smaller

[racnan]

Backwards compatibility ?

[ThisIsMani]

Backwards compatibility ?

In sandbox,
total emails > 7000
emails with uppercase = 229
emails with uppercase + their lowercase counterparts = 306
single emails with uppercase = 152

We will be replacing all the 152 users with their lowercase emails.

Since any of the invited users in sandbox are not having uppercase letters, we will be not touching the users with multiple emails with different cases. And they will only be able to login to their lowercase emails.