Confusion will no longer continue to confuse after being cured (#52286)

* Confusion will no longer continue to confuse after being cured

* Grammar comment fix

* Move to status effect

* Remove test per request

* Make confusion a status effect, confusion curing now completely neuters the confusion

* set_confusion changes, get_confusion

* Fix confusion going down twice per tick

* Change strength = to proc

* Move procs to status_procs

code/modules/unit_tests/_unit_tests.dm

@@ -15,6 +15,7 @@
 #include "card_mismatch.dm"
 #include "chain_pull_through_space.dm"
 #include "component_tests.dm"
+#include "confusion.dm"
 #include "keybinding_init.dm"
 #include "medical_wounds.dm"
 #include "metabolizing.dm"

code/modules/unit_tests/confusion.dm

@@ -0,0 +1,16 @@
+// Checks that the confusion symptom correctly gives, and removes, confusion
+/datum/unit_test/confusion_symptom/Run()
+	var/mob/living/carbon/human/H = allocate(/mob/living/carbon/human)
+	var/datum/disease/advance/confusion/disease = allocate(/datum/disease/advance/confusion)
+	var/datum/symptom/confusion/confusion = disease.symptoms[1]
+	disease.processing = TRUE
+	disease.update_stage(5)
+	disease.infect(H, make_copy = FALSE)
+	confusion.Activate(disease)
+	TEST_ASSERT(H.get_confusion() > 0, "Human is not confused after getting symptom.")
+	disease.cure()
+	TEST_ASSERT_EQUAL(H.get_confusion(), 0, "Human is still confused after curing confusion.")
+
+/datum/disease/advance/confusion/New()
+	symptoms += new /datum/symptom/confusion
+	Refresh()