Resourceadm: Making concurrent saves can corrupt the file-system files

[Alxandr]

Description of the bug

Making a lot of concurrent changes produces a invalid JSON.

Steps To Reproduce

1. Go to a resource
2. Scroll down to the "visible" toggle
3. Click it like crazy
4. Reload after you get an error message
5. If reloading works, go back to 2.

Additional Information

No response