Allow to stop running workflow (#15270)

https://github.com/user-attachments/assets/599154e4-8743-471b-b05a-721b635bcf4e

On stoppage:
- if no running steps, mark pending as failed and end the workflow
- if running steps, set as stopping and exit. Going to the next step, as
the workflow is not running anymore, it will naturally stop

packages/twenty-server/src/engine/core-modules/metrics/types/metrics-keys.type.ts

@@ -19,6 +19,7 @@ export enum MetricsKeys {
   WorkflowRunStartedManualTrigger = 'workflow-run/started/manual-trigger',
   WorkflowRunCompleted = 'workflow-run/completed',
   WorkflowRunFailed = 'workflow-run/failed',
+  WorkflowRunStopped = 'workflow-run/stopped',
   WorkflowRunFailedThrottled = 'workflow-run/failed/throttled',
   WorkflowRunFailedToEnqueue = 'workflow-run/failed/to-enqueue',
   AIToolExecutionFailed = 'ai-tool-execution/failed',