Cloud billing trial period & free plan

[paolodamico]

Changes

This PR sets the relevant environment variables to accomplish the following:

• Sets the event allocation of the free plan at 10,000 events. This means that after Billing page improvements #3192 any organization that exceeds 8.5k events in a month will get a billing alert prompting them to singup for our Standard Plan (i.e. enter their card details).

Checklist

• All querysets/queries filter by Organization, by Team, and by User
• Django backend tests
• Jest frontend tests
• Cypress end-to-end tests

[jamesefhawkins]

Free event allocation

Looks good.

Free trial

The more I think about it, I'm not convinced the free trial makes sense.

When I've priced based on pure usage, I've not had a single person ask for this yet (as they could just try it with a few events for example), and "multiple projects" or "SSO" are quite self explanatory features.

So I'd probably not do this unless there's an argument the other way?

[Twixes]

From a product perspective, I'm also not convinced the free trial will be more useful than confusing, since we also have the free portion of events.

[paolodamico]

Agreed on both arguments @Twixes & @jamesefhawkins, think it makes sense, the free trial aspect is already included in the free 10k events per month. Removing free trial period.