improvement for cryo squad marines cryoning and some minor QOL for ra…

…dnomiz_squad proc (#7911)

# About the pull request
Fix issue with marines without squad and prev strange code, that
unlocked prev by my own mistake locked code

# Explain why it's good for the game
Less bugs, better

# Changelog

:cl:
code: randomize_squad code qol
fix: In case if for some reason we have less open slots in squads for
jobs than jobs aval in total, we put in to cryo squad in assumption that
this their marine did cryo
/:cl:

Closes #8055
Closes #7283

code/game/jobs/role_authority.dm

@@ -545,32 +545,26 @@ I hope it's easier to tell what the heck this proc is even doing, unlike previou
 	for(var/datum/squad/squad in squads)
 		if(squad.roundstart && squad.usable && squad.faction == human.faction && squad.name != "Root")
 			mixed_squads += squad
-	mixed_squads = shuffle(mixed_squads)
 
-	var/preferred_squad
-	if(human?.client?.prefs?.preferred_squad)
-		preferred_squad = human.client.prefs.preferred_squad
+	var/preferred_squad = human.client?.prefs?.preferred_squad
+	if(preferred_squad == "None")
+		preferred_squad = null
 
 	var/datum/squad/lowest
 	for(var/datum/squad/squad in mixed_squads)
 		if(slot_check && !isnull(squad.roles_cap[slot_check]) && !skip_limit)
 			if(squad.roles_in[slot_check] >= squad.roles_cap[slot_check])
 				continue
 
-		if(squad.name == preferred_squad || squad.equivalent_name == preferred_squad) //fav squad or faction equivalent has a spot for us, no more searching needed.
+		if(preferred_squad && (squad.name == preferred_squad || squad.equivalent_name == preferred_squad)) //fav squad or faction equivalent has a spot for us, no more searching needed.
 			if(squad.put_marine_in_squad(human))
 				return
 
-		if(!lowest)
+		if(!lowest || (slot_check && lowest.roles_in[slot_check] > squad.roles_in[slot_check]))
 			lowest = squad
-
-		else if(slot_check)
-			if(squad.roles_in[slot_check] < lowest.roles_in[slot_check])
-				lowest = squad
-
-	if(!lowest || !lowest.put_marine_in_squad(human))
-		to_world("Warning! Bug in get_random_squad()!")
-		return
+	if(!lowest)
+		lowest = locate(/datum/squad/marine/cryo) in squads
+	lowest.put_marine_in_squad(human)
 	return
 
 /datum/authority/branch/role/proc/get_caste_by_text(name)