feat(user): implement change password for user

[apoorvdixit88]

Type of Change

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

Description

Added functionality for changing password for user. User the update their old passwords.

Additional Changes

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

Motivation and Context

There is no functionality to update password for user.

How did you test it?

Tested locally:

• First do signup or signin to existing account

curl --location 'http://localhost:8080/user/v2/signin' \
--header 'Content-Type: application/json' \
--header 'Cookie: token=JWT' \
--data-raw '{
    "email": "newuser2@juspay.in",
    "password": "Test@12345"
    
}'

• Call change password, pass old and new password in json body

curl --location 'http://localhost:8080/user/change_password' \
--header 'Content-Type: application/json' \
--header 'Cookie: token=JWT' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoiM2JlZGViOTktNmI0My00ZGJmLTlhNjgtMWM0MDU1ODEzZDU1IiwibWVyY2hhbnRfaWQiOiJtZXJjaGFudF8xNzAwNzI2NDUzIiwicm9sZV9pZCI6Im9yZ19hZG1pbiIsImV4cCI6MTcwMDg5OTI1NCwib3JnX2lkIjoib3JnX3JEa3VYa09hTElRT1RISHBvYXRhIn0.1QWrzj4FSibTvi7jTU8cJSJjV5tk7Ns1vitl2qHSEYY' \
--data-raw '{
    "new_password": "Test@12345",
    "old_password": "Test@1406"
}
'

• Again try to signin with new password
  Use the signin curl again.

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

[ThisIsMani]

Can we fix this order