Fix: Resolve issue with "Update Subscription" button being always disabled for Stripe

[pauloiankoski]

Resolves GIVE-1326

Description

This PR fixes an issue where the “Update Subscription” button was always disabled, preventing users from updating subscription amounts. The issue affected both the Option Based Form Editor (V2) and the Visual Form Builder (VFB) forms.

The problem stemmed from a recently introduced id property in the subscription status object, which will only be available in the next release of Give Recurring. To ensure backwards compatibility, this fix adds a fallback to use a lowercased version of the label property when id is not present.

With this adjustment, the “Update Subscription” button will be correctly enabled, allowing users to update subscription amounts as expected, regardless of whether their data includes the new id property.

Affects

Manage Subscription on the Donor Dashboard

Testing Instructions

1. Create a subscription.
2. Go to the Donor Dashboard.
3. Click the “Manage Subscription” link.
4. The “Update Subscription” button should now be enabled (the subscription must have an active status).

Pre-review Checklist

• Acceptance criteria satisfied and marked in related issue
• Relevant @unreleased tags included in DocBlocks
• Includes unit tests
• Reviewed by the designer (if follows a design)
• Self Review of code and UX completed

[JoshuaHungDinh]

Good to go!

[rickalday]

Passed manual QA tests.