Delete workflow step (#7373)

- Allows the deletion of triggers and steps in workflows. If the
workflow can not be edited right now, we create a new draft version.
- The workflow right drawer can now render nothing. It's necessary to
behave that way because a deleted step will still be displayed for a
short amount of time in the drawer. The drawer will be filled with blank
content when it disappears.


https://github.com/user-attachments/assets/abd5184e-d3db-4fe7-8870-ccc78ff23d41

Closes #7057

packages/twenty-front/src/modules/workflow/hooks/useDeleteOneStep.tsx

@@ -0,0 +1,76 @@
+import { CoreObjectNameSingular } from '@/object-metadata/types/CoreObjectNameSingular';
+import { useUpdateOneRecord } from '@/object-record/hooks/useUpdateOneRecord';
+import { TRIGGER_STEP_ID } from '@/workflow/constants/TriggerStepId';
+import { useCreateNewWorkflowVersion } from '@/workflow/hooks/useCreateNewWorkflowVersion';
+import {
+  WorkflowVersion,
+  WorkflowWithCurrentVersion,
+} from '@/workflow/types/Workflow';
+import { removeStep } from '@/workflow/utils/removeStep';
+
+export const useDeleteOneStep = ({
+  stepId,
+  workflow,
+}: {
+  stepId: string;
+  workflow: WorkflowWithCurrentVersion;
+}) => {
+  const { updateOneRecord: updateOneWorkflowVersion } =
+    useUpdateOneRecord<WorkflowVersion>({
+      objectNameSingular: CoreObjectNameSingular.WorkflowVersion,
+    });
+
+  const { createNewWorkflowVersion } = useCreateNewWorkflowVersion({
+    workflowId: workflow.id,
+  });
+
+  const deleteOneStep = async () => {
+    if (workflow.currentVersion.status !== 'DRAFT') {
+      const newVersionName = `v${workflow.versions.length + 1}`;
+
+      if (stepId === TRIGGER_STEP_ID) {
+        await createNewWorkflowVersion({
+          name: newVersionName,
+          status: 'DRAFT',
+          trigger: null,
+          steps: workflow.currentVersion.steps,
+        });
+      } else {
+        await createNewWorkflowVersion({
+          name: newVersionName,
+          status: 'DRAFT',
+          trigger: workflow.currentVersion.trigger,
+          steps: removeStep({
+            steps: workflow.currentVersion.steps ?? [],
+            stepId,
+          }),
+        });
+      }
+
+      return;
+    }
+
+    if (stepId === TRIGGER_STEP_ID) {
+      await updateOneWorkflowVersion({
+        idToUpdate: workflow.currentVersion.id,
+        updateOneRecordInput: {
+          trigger: null,
+        },
+      });
+    } else {
+      await updateOneWorkflowVersion({
+        idToUpdate: workflow.currentVersion.id,
+        updateOneRecordInput: {
+          steps: removeStep({
+            steps: workflow.currentVersion.steps ?? [],
+            stepId,
+          }),
+        },
+      });
+    }
+  };
+
+  return {
+    deleteOneStep,
+  };
+};