Mirrored on Skyrat: Skyrat-SS13/Skyrat-tg#25216
Original PR: tgstation/tgstation#79862

About The Pull Request

Yup this is the last time I'll lay hands on holder.dm after 2 rounds of code compression the file was still over 2000 lines long so now the next best thing to reduce it is organizing procs into logical files, that and even more proc removals. As you can see we are still able to reduce code size even further

1. Removes & merges expose_multiple() proc into expose()
Th only difference between these 2 procs is that expose() uses all reagents inside the holder whereas expose_multiple() uses a select few reagents. We can just add a 4th parameter to expose() that will accept a list of reagents thus achieving the same results and that was done reducing overall code

2. Removes conditonal_update() proc & on_update() proc
The proc on_update() definition is empty and no reagent was overriding it and as a result conditonal_update() that calls this proc is also functionally useless therefore both of these procs were removed reducing overall code

3. Finally splits holder.dm into logical files under the folder code/modules/reagents/holder

• holder.dm: this is the still the file for core functionality it's just now moved into this new folder. Added comments to group procs under separate categories for easy readability.
• mob_life.dm: contains reagent code for metabolizing reagents and for handling stasis
• reactions.dm: all code for reagents reacting inside the holder
• properties.dm: procs for editing/reading the volume, temperature, ph, purity properties of reagents inside the holder, also for reading its taste description
• ui_data.dm: all code for displaying & interacting with reagent data via UI

Changelog

🆑 SyncIt21
code: removes & merges expose_multiple() proc into expose() proc inside reagent holder
code: removes conditonal_update() proc & on_update() proc inside reagent holder and reagent
refactor: Reagent code has been trimmed and split into multiple files. report bugs on github
/:cl: