Feature: set donation type as category to GA event

[ravinderk]

Resolves #47

Description

This pull request implements Google Analytics tracking for renewals. A category (One-Time, Subscription, or Renewal) will be added to item information.

Pre-review Checklist

• [x] 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)
• [x] Self Review of code and UX completed

[ravinderk]

Looks solid, @ravinderk! Let's get this over to QA!

👍

[ravinderk]

@JasonTheAdams After debugging the Google Analytic event data, I found a few bugs which have been fixed.

• For renewal donations, the refund and purchase event do not appear in the real-time dashboard because client id and session id was incorrect. I was fetching them from renewal donation metadata instead of parent donation metadata.
• item_category_3 has an incorrect value for the subscription because I was looking for the subscription id in the donation model, but it does not set for subscription initial payment.
• item_category_3 does not track correctly for an item for iframe donation on the frontend because I did not add logic. It is working only for the legacy form template.

Note: For renewal donation, refund and purchase events will appear in the real-time dashboard in Google analytics.