clean code and normalize billing eventNames (#9928)

Solves :
https://github.com/twentyhq/private-issues/issues/251

**TLDR:**

Clean Billing Code using feedback of the previous PR (#9865). Normalized
the metadata and names of the products, prices, and meters in Stripe so
that they can be accessed in stripe's test mode and live mode.

**In order to test:**

1. Have the environment variable IS_BILLING_ENABLED set to true and add
the other required environment variables for Billing to work
2. Do a database reset (to ensure that the new feature flag is properly
added and that the billing tables are created)
3. Run the command: npx nx run twenty-server:command
billing:sync-plans-data (if you don't do that the products and prices
will not be present in the database)
4. Run the server , the frontend, the worker, and the stripe listen
command (stripe listen --forward-to
http://localhost:3000/billing/webhooks)
5. Buy a subscription for the Acme workspace
6. Create a workflow and run it
7. After the run has been finished check in sprite the quantity of
events in the CreditMeter, you should see that there is a new occurence
with value one.

packages/twenty-server/src/modules/workflow/workflow-runner/workspace-services/workflow-runner.workspace-service.ts

@@ -27,10 +27,10 @@ export class WorkflowRunnerWorkspaceService {
     payload: object,
     source: ActorMetadata,
   ) {
-    const canExecuteBilledFunction =
-      await this.billingUsageService.canExecuteBilledFunction(workspaceId);
+    const canFeatureBeUsed =
+      await this.billingUsageService.canFeatureBeUsed(workspaceId);
 
-    if (!canExecuteBilledFunction) {
+    if (!canFeatureBeUsed) {
       this.logger.log(
         'Cannot execute billed function, there is no subscription for this workspace',
       );