[Ninja Request] Allow portables to be placed on flowers/fires

Some players like to troll by putting fires or flowers where others would like to place portables (especially w2 burthorpe at day reset). So I propose that portables be given priority. If you try to place a portable on a tile that already has a flower/fire, the flower/fire would despawn and the portable would be placed.

Of course this would open up a reverse kind of trolling - placing a portable on top of a fire that someone was trying to use for cooking/bonfires. So maybe portables could only be placed on a fire if there is at least one fire adjacent to it.