Begin integration of google analytics LBC-324

[Moggach]

Description

This PR begins the process of integrating Google Analytics 4 reporting into LBC
Steps taken:

1. Add google analytics tracking code to base.html
2. We have default acquisition and engagement data

3. I added some GA4 events to measure some key ecommerce events on the site e.g. membership purchase, donation, gift membership purchase
4. Most of these load when certain pages load e.g. completed_membership_purchase.html
5. I've been using these docs as a guide
   https://developers.google.com/analytics/devguides/collection/ga4/reference/events?client_type=gtag
   https://stripe.com/docs/payments/checkout/analyze-conversion-funnel
   although possibly there's a better way to do this on the server side using webhooks or similar. I wasn't sure.

Further steps to take based on current implementation:

1. Work out a way to generate a unique transaction ID - I wondered if this could be based on a stripe transaction ID and whether this is available in the template?
2. Test that these events are being reported to Google Analytics with the relevant data to make them useful e.g. items purchase, value of transaction etc

NB there is a purchase event from yesterday which was probably me accidentally buying a book and then refunding it. That indicates that there may be some default ecommerce reporting active. There's no product data associated with it though

Motivation and Context

Linked to issue LBC-324

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[linear]

LBC-324 Integrate Stripe subscriptions and purchases with GA4

This article looks like a good place to start

https://stripe.com/docs/payments/checkout/analyze-conversion-funnel#instrumentation-using-google-analytics

We have engagement

Untitled 2.png

The next step is monetisation

Untitled.png