fix(request): try to use persisted queries variables when request.var…

[gtkatakura]

Description

• I was testing the new changes in real use cases. I noticed that some implementations as the apollo persisted queries send both extensions.variables and variables together. So I added some support to try to use the extensions.variables if the variables is an empty object.

Screenshot

Checklist

• [x] Displays correctly with both dark and light mode (see useTheme.ts)
• [ ] Unit/Integration tests added

[warrenday]

Thanks @gtkatakura