[BUG] saltclass tops state list is incomplete for nested classes

[cheribral]

Description
When using saltclass with multiple levels of classes, all of which define states, the resulting state list only comes back with states for the top level classes. Looking at the code, it appears that it is ignoring the state lists returned from the recursive calls of expand_classes_in_order

Setup

Node: 
  classes: [A,L]

Class A:
  states: [1,2]
  classes: [B]
Class B:
  states: [3,4]
  classes: [C]
Class C:
  states: [5,6]
 
Class: L
  states: [7]
  classes: [M]
Class M:
  states: [8]

Expected behavior
Running state.show_top with the above classes, one would expect a state list of [1,2,3,4,5,6,7,8], but what comes back instead is [1,2,7]

Versions Report

salt --versions-report

Salt Version:
           Salt: 3002.1
 
Dependency Versions:
           cffi: 1.14.2
       cherrypy: Not Installed
       dateutil: 2.8.1
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.11.1
        libgit2: 0.28.2
       M2Crypto: 0.35.2
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.6.2
   mysql-python: Not Installed
      pycparser: 2.20
       pycrypto: 2.6.1
   pycryptodome: 3.9.7
         pygit2: 0.28.2
         Python: 3.6.8 (default, Oct 13 2020, 16:18:22)
   python-gnupg: Not Installed
         PyYAML: 3.13
          PyZMQ: 17.0.0
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.1.4
 
System Versions:
           dist: centos 7 Core
         locale: UTF-8
        machine: x86_64
        release: 3.10.0-1160.2.2.el7.x86_64
         system: Linux
        version: CentOS Linux 7 Core

Additional context
Without knowing exactly what was intended, this is my rough guess as to what might have been meant to happen:

--- salt/utils/saltclass.py        2020-11-18 04:04:34.890045089 +0000
+++ -   2020-11-18 04:04:47.691585445 +0000
@@ -311,7 +311,7 @@
             if expanded_classes[klass].get("classes"):
                 l_id = classes_to_expand.index(klass)
                 classes_to_expand[l_id:l_id] = expanded_classes[klass]["classes"]
-                expand_classes_in_order(
+                _,_,minion_dict["states"] = expand_classes_in_order(
                     minion_dict,
                     salt_data,
                     seen_classes,
@@ -319,7 +319,7 @@
                     classes_to_expand,
                 )
             else:
-                expand_classes_in_order(
+                _,_,minion_dict["states"] = expand_classes_in_order(
                     minion_dict,
                     salt_data,
                     seen_classes,
@@ -347,7 +347,7 @@
             "states" in expanded_classes[ord_klass]
             and expanded_classes[ord_klass]["states"] is None
         ):
-            expanded_classes[ord_klass]["states"] = {}
+            expanded_classes[ord_klass]["states"] = []
 
         if "states" in expanded_classes[ord_klass]:
             ord_expanded_states.extend(expanded_classes[ord_klass]["states"])
@@ -357,7 +357,9 @@
         minion_dict["states"] = []
 
     if "states" in minion_dict:
-        ord_expanded_states.extend(minion_dict["states"])
+        for state in minion_dict["states"]:
+            if state not in ord_expanded_states:
+                ord_expanded_states.append(state)
 
     ord_expanded_classes.append(minion_dict)