Quality support for radius_visualisation_specification

[thesixthroc]

In Cerys, higher-quality towers have a larger heating range.

For the player-constructible towers that the player can hold in their cursor, the current value of radius_visualisation_specification.distance is 15, which matches their actual heating range at Normal quality.

It would be fantastic for Cerys and other mods if this radius visualization could be assigned a quality scaling so that it is not inaccurate for higher qualities.