Allow users to cancel pending orders

[syedgalib]

PR Type

What kind of change does this PR introduce?

• Bugfix
• Security fix
• Improvement
• New Feature
• Refactoring (no functional changes, no api changes)
• Build related changes
• Text changes
• Other... Please describe:

Description

How to reproduce the issue or how to test the changes

1. Visit the checkout page with checkout_type=payment and confirm the secondary action label remains Not Now.
2. Visit the checkout page with another valid checkout type and confirm the secondary action label is Cancel.
3. Open the user dashboard orders table with a pending order. Confirm the actions menu shows Pay and Cancel, and that Pay opens checkout with checkout_type=payment&order_id={id}.
4. Click Cancel, confirm the modal, and verify the pending order status changes to cancelled. Confirm non-pending orders cannot be cancelled.

Any linked issues

N/A

Checklist

• My code follows the WordPress coding standards