refactor(core): Make placeholders in manual executions in workers temporary

[ivov]

Summary

Please see details in story.

To test:

0. Get workflow and payload attached in Slack.
1. Set up a dummy server:

mkdir ~/Downloads/dummy
mv ~/Downloads/large-wf-data.json ~/Downloads/dummy
cd ~/Downloads/dummy
python3 -m http.server 3000

2. Start a main in queue mode with OFFLOAD_MANUAL_EXECUTIONS_TO_WORKERS=true and import the workflow.
3. Start a worker.
4. Run the workflow manually.

Expected: See acceptance criteria in the story.

Related Linear tickets, Github issues, and Community forum posts

https://linear.app/n8n/issue/PAY-2429

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[codecov]

Codecov Report

Attention: Patch coverage is 30.90909% with 38 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ges/editor-ui/src/composables/usePushConnection.ts	16.66%	20 Missing ⚠️
packages/editor-ui/src/components/RunData.vue	18.18%	9 Missing ⚠️
packages/cli/src/push/index.ts	0.00%	5 Missing ⚠️
packages/editor-ui/src/stores/workflows.store.ts	50.00%	4 Missing ⚠️

📢 Thoughts on this report? Let us know!

[ivov]

I know this is not ideal, but it minimizes the extent of changes to make. pushMessageReceived is in dire need of refactoring.