Add billing meter event service (#9865)

Solves :
https://github.com/twentyhq/private-issues/issues/241
https://github.com/twentyhq/private-issues/issues/254

**TLDR:**

- Add BillingMeterEventService and StripeBillingMeterEventService in
order to send billing meter events to stripe.
- Plugged the service into workflow node execution for testing purposes
(more improvements on this area will be done in the next PR's)

**In order to test:**

- Have the environment variable IS_BILLING_ENABLED set to true and add
the other required environment variables for Billing to work
- Do a database reset (to ensure that the new feature flag is properly
added and that the billing tables are created)
- 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)
- Run the server , the frontend, the worker, and the stripe listen
command (stripe listen --forward-to
http://localhost:3000/billing/webhooks)
- Buy a subscription for the Acme workspace 
- Create a workflow and run it
- 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.

**Take into consideration:**

- I used an eventName that I have made a long time ago, so it hasn't a
significant naming. I'm updating the meters and associated prices in
stripe to use the correct meter with a more clearer eventName.
- I put some error handling in the execution of the workflow nodes, this
is still incomplete and needs some refinement, I would like the feedback
of the workflows track for a more cleaner approach

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

@@ -1,5 +1,10 @@
 import { Injectable, Logger } from '@nestjs/common';
 
+import { BILLING_EXECUTE_BILLED_FUNCTION } from 'src/engine/core-modules/billing/constants/billing-execute-billed-function.constant';
+import { BillingMeterEventName } from 'src/engine/core-modules/billing/enums/billing-meter-event-names';
+import { BillingUsageEvent } from 'src/engine/core-modules/billing/types/billing-usage-event.type';
+import { ScopedWorkspaceContextFactory } from 'src/engine/twenty-orm/factories/scoped-workspace-context.factory';
+import { WorkspaceEventEmitter } from 'src/engine/workspace-event-emitter/workspace-event-emitter';
 import {
   WorkflowRunOutput,
   WorkflowRunStatus,
@@ -19,7 +24,11 @@ export type WorkflowExecutorOutput = {
 @Injectable()
 export class WorkflowExecutorWorkspaceService {
   private readonly logger = new Logger(WorkflowExecutorWorkspaceService.name);
-  constructor(private readonly workflowActionFactory: WorkflowActionFactory) {}
+  constructor(
+    private readonly workflowActionFactory: WorkflowActionFactory,
+    private readonly workspaceEventEmitter: WorkspaceEventEmitter,
+    private readonly scopedWorkspaceContextFactory: ScopedWorkspaceContextFactory,
+  ) {}
 
   async execute({
     currentStepIndex,
@@ -64,6 +73,10 @@ export class WorkflowExecutorWorkspaceService {
       result.error?.errorMessage ??
       (result.result ? undefined : 'Execution result error, no data or error');
 
+    if (!error) {
+      this.sendUsageEvent();
+    }
+
     const updatedStepOutput = {
       id: step.id,
       name: step.name,
@@ -122,4 +135,20 @@ export class WorkflowExecutorWorkspaceService {
 
     return { ...updatedOutput, status: WorkflowRunStatus.FAILED };
   }
+
+  async sendUsageEvent() {
+    const workspaceId =
+      this.scopedWorkspaceContextFactory.create().workspaceId ?? '';
+
+    this.workspaceEventEmitter.emitCustomBatchEvent<BillingUsageEvent>(
+      BILLING_EXECUTE_BILLED_FUNCTION,
+      [
+        {
+          eventName: BillingMeterEventName.WORKFLOW_NODE_RUN,
+          value: 1,
+        },
+      ],
+      workspaceId,
+    );
+  }
 }