Refactors Regenerate Organs, and a few organ helpers (#74219)

## About The Pull Request

Refactors regenerate organs to be slightly more intelligent in handling
organ changes and replacements.
Noteably:
- We don't remove organs that were modified by the owner; such as
changing out your heart for a cybernetic
- We early break out of the for loop if they aren't supposed to have an
organ there and remove it
- We check for the organ already being correct, and just healing it and
continuing if it is

Also changes the names of some of the organ helpers into snake_case
### Mapping March
Ckey to receive rewards: N/A

## Why It's Good For The Game
## Changelog

---------

Co-authored-by: Jacquerel <hnevard@gmail.com>

code/modules/mod/modules/modules_medical.dm

@@ -201,7 +201,7 @@
 			succeed = TRUE
 			break
 	if(succeed)
-		var/list/organs_to_boot_out = organ_receiver.getorganslot(organ.slot)
+		var/list/organs_to_boot_out = organ_receiver.get_organ_slot(organ.slot)
 		for(var/obj/item/organ/organ_evacced as anything in organs_to_boot_out)
 			if(organ_evacced.organ_flags & ORGAN_UNREMOVABLE)
 				continue