* Add self billing feature flag * Add two core tables for billing * Remove useless imports * Remove graphql decorators * Rename subscriptionProduct table * WIP: Add stripe config * Add controller to get product prices * Add billing service * Remove unecessary package * Simplify stripe service * Code review returns * Use nestjs param * Rename subscription to basePlan * Rename env variable * Add checkout endpoint * Remove resolver * Merge controllers * Fix security issue * Handle missing url error * Add workspaceId in checkout metadata * Add BILLING_STRIPE_WEBHOOK_SECRET env variable * WIP: add webhook endpoint * Fix body parser * Create Billing Subscription on payment success * Set subscriptionStatus active on webhook * Add useful log --------- Co-authored-by: Charles Bochet <charles@twenty.com>