Deadmin tweaks: Admins without +AUTOLOGIN start deadmined. AUTOLOGIN defaults to on. (#33480)

* Deadmin tweaks, Admins without +ADMIN start deadmined.
Deadmining no longer destroys the admin datum.
Admins without +ADMIN start deadmined, reloading admins re-deadmins them.
Moved some code around to make it more sane
People with +PERMISSION can now deadmin or readmin other admins at will.

* Adds new flag for if the role should automatically log in, defaults to on, can be removed with -AUTOLOGIN
Also fixes a bug in permission panel not handling these cases gracefully

code/modules/admin/admin_verbs.dm

@@ -638,12 +638,7 @@ GLOBAL_LIST_INIT(admin_verbs_hideable, list(
 	if(has_antag_hud())
 		toggle_antag_hud()
 
-	holder.disassociate()
-	qdel(holder)
-
-	GLOB.deadmins += ckey
-	GLOB.admin_datums -= ckey
-	verbs += /client/proc/readmin
+	holder.deactivate()
 
 	to_chat(src, "<span class='interface'>You are now a normal player.</span>")
 	log_admin("[src] deadmined themself.")
@@ -655,13 +650,20 @@ GLOBAL_LIST_INIT(admin_verbs_hideable, list(
 	set category = "Admin"
 	set desc = "Regain your admin powers."
 
-	load_admins(ckey)
+	var/datum/admins/A = GLOB.deadmins[ckey]
 
-	if(!holder) // Something went wrong...
-		return
+	if(!A)
+		A = GLOB.admin_datums[ckey]
+		if (!A)
+			var/msg = " is trying to readmin but they have no deadmin entry"
+			message_admins("[key_name_admin(src)][msg]")
+			log_admin_private("[key_name(src)][msg]")
+			return
 
-	GLOB.deadmins -= ckey
-	verbs -= /client/proc/readmin
+	A.associate(src)
+
+	if (!holder)
+		return //This can happen if an admin attempts to vv themself into somebody elses's deadmin datum by getting ref via brute force
 
 	to_chat(src, "<span class='interface'>You are now an admin.</span>")
 	message_admins("[src] re-adminned themselves.")