fix(router): validate schedule time before scheduling API key expiry reminder

[trfdeer]

Type of Change

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

Description

During the api_key expiry if the merchant sets the expiry to next day or any other day before 7 days, we need to perform a validation something like - calculate the schedule_time of 1st email during api_key creation. if it is before the current_time, don't create an entry in process_tracker.

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 #1625

How did you test it?

I tested the changes manually.

1. First created an API Key with expiry date after more than 7 days from today. Verified process_tracker entry is added.
   
   
   
   

2. Then created an API key with expiry date less than 7 days from today. Verified process_tracker entry is not added.
   
   

Checklist

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

[Chethan-rao]

Just add the comment saying that if merchant wants the api_key to expire before 7 days, then we are not notifying the merchant about its expiry, so that we document this action.

Other than that, looks good to me!

[trfdeer]

Just add the comment saying that if merchant wants the api_key to expire before 7 days, then we are not notifying the merchant about its expiry, so that we document this action.

I've added comments describing the change.

[SanchithHegde]

Looks good to me!

Thanks for the PR, @trfdeer!