Introduce today_or_future? method

[olimart]

Motivation / Background

This Pull Request introduces a convenient helper to check if a date/time is either today or in the future.

Drawing inspiration from #46786 which introduces .local? helper for environment check.

Detail

This Pull Request changes:

• ActiveSupport::TimeWithZone
• DateAndTime::Calculations

Additional information

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• Tests are added or updated if you fix a bug or add a feature.
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.

[olimart]

👋 @rafaelfranca would Rails be interested by such helper?
If so, do we need tests? (given the underlying methods are already tested)

[zzak]

In my experience, there has to be a really good use-case to add new features to Active Support.

Either by way of solving a really common and user-unfriendly experience in the application, or addressing the needs of the frameworks and ecosystem of Rails.

If that hasn't been found for this feature it will probably be closed.

[rafaelfranca]

Yeah, multiple versions of those methods were already proposed. So far, we have no reason to believe that they are necessary. Thank you for the pull request