* Opacity refactor (#52881)
Moves all opacity var manipulation to a proc which sends a signal.
light_blocker element for movable opaque atoms made, which tracks its movement and updates the affected turfs for proper lighting updates.
has_opaque_atom boolean replaced by the opacity_sources lazylist to keep track of the sources, and a directional_opacity which serves a similar function but also allows for future expansion with on-border opaque objects (not yet implemented).
Some opacity-related sight procs optimized as a result of this.
Some variables moved to the object's definition.
A define or two added into the mix for clarity.
Some code cleaning, like turning booleans into their defines.
One file renamed for clarity.
Changelog
cl
balance: Mechs no longer block sight. It's a non-trivial cost for the lighting system with little to no gain.
/cl
* Opacity refactor
Co-authored-by: Rohesie <rohesie@gmail.com>
