[FIX] Add food heating to grid furnitures

[leoCottret]

Summary

SUMMARY: Bugfixes "Add food heating when eating to grid RV kitchen and oven"

Purpose of change

Fixes #1564

Describe the solution

When eating close to a RV kitchen or oven, the food will be automatically heated like with their vehicles counterpart.
If a fire is lit, no power is used.
If there isn't, it will use 25 power (same as the vehicle version).
When no power is left, it doesn't heat the food.

Testing

I tested the different conditions described in the solution

[Coolthulhu]

I didn't notice when it happened, but apparently heating food consumes 25 kJ now. That's quite a lot.

[leoCottret]

Yes I just set it as 25 for consistency.
Although, the final result multiplies by 5 the json value, I wonder if it's a bug, and/or what's the logic behind it