Maintain footer

Ensure footer gets deliverd to AMQP client as received from AMQP client
when feature flag message_containers_store_amqp_v1 is disabled.

Fixes test
```
bazel test //deps/rabbit:amqp_system_SUITE-mixed  -t- --test_sharding_strategy=disabled --test_env FOCUS="-group [dotnet] -case footer"
```

deps/rabbit/src/mc_amqpl.erl

@@ -39,6 +39,7 @@
 -define(AMQP10_PROPERTIES_HEADER, <<"x-amqp-1.0-properties">>).
 -define(AMQP10_APP_PROPERTIES_HEADER, <<"x-amqp-1.0-app-properties">>).
 -define(AMQP10_MESSAGE_ANNOTATIONS_HEADER, <<"x-amqp-1.0-message-annotations">>).
+-define(AMQP10_FOOTER, <<"x-amqp-1.0-footer">>).
 -define(PROTOMOD, rabbit_framing_amqp_0_9_1).
 -define(CLASS_ID, 60).
 
@@ -56,30 +57,29 @@ init(#content{} = Content0) ->
     {strip_header(Content, ?DELETED_HEADER), Anns}.
 
 convert_from(mc_amqp, Sections, Env) ->
-    {H, MAnn, Prop, AProp, BodyRev} =
-        lists:foldl(
-          fun
-              (#'v1_0.header'{} = S, Acc) ->
-                  setelement(1, Acc, S);
-              (#'v1_0.message_annotations'{} = S, Acc) ->
-                  setelement(2, Acc, S);
-              (#'v1_0.properties'{} = S, Acc) ->
-                  setelement(3, Acc, S);
-              (#'v1_0.application_properties'{} = S, Acc) ->
-                  setelement(4, Acc, S);
-              (#'v1_0.delivery_annotations'{}, Acc) ->
-                  %% delivery annotations not currently used
-                  Acc;
-              (#'v1_0.footer'{}, Acc) ->
-                  %% footer not currently used
-                  Acc;
-              (undefined, Acc) ->
-                  Acc;
-              (BodySection, Acc) ->
-                  Body = element(5, Acc),
-                  setelement(5, Acc, [BodySection | Body])
-          end, {undefined, undefined, undefined, undefined, []},
-          Sections),
+    {H, MAnn, Prop, AProp, BodyRev, Footer} =
+    lists:foldl(
+      fun(#'v1_0.header'{} = S, Acc) ->
+              setelement(1, Acc, S);
+         (#'v1_0.message_annotations'{} = S, Acc) ->
+              setelement(2, Acc, S);
+         (#'v1_0.properties'{} = S, Acc) ->
+              setelement(3, Acc, S);
+         (#'v1_0.application_properties'{} = S, Acc) ->
+              setelement(4, Acc, S);
+         (#'v1_0.delivery_annotations'{}, Acc) ->
+              %% delivery annotations not currently used
+              Acc;
+         (#'v1_0.footer'{} = S, Acc) ->
+              setelement(6, Acc, S);
+         (undefined, Acc) ->
+              Acc;
+         (BodySection, Acc) ->
+              Body = element(5, Acc),
+              setelement(5, Acc, [BodySection | Body])
+      end,
+      {undefined, undefined, undefined, undefined, [], undefined},
+      Sections),
 
     {PayloadRev, Type0} =
         case BodyRev of
@@ -188,7 +188,14 @@ convert_from(mc_amqp, Sections, Env) ->
                                          MAnnBin = iolist_to_binary(amqp10_framing:encode_bin(MAnn)),
                                          [{?AMQP10_MESSAGE_ANNOTATIONS_HEADER, longstr, MAnnBin} | Headers4]
                                  end,
-                      Headers5;
+                      Headers6 = case Footer of
+                                     undefined ->
+                                         Headers5;
+                                     #'v1_0.footer'{} ->
+                                         FootBin = iolist_to_binary(amqp10_framing:encode_bin(Footer)),
+                                         [{?AMQP10_FOOTER, longstr, FootBin} | Headers5]
+                                 end,
+                      Headers6;
                   _ ->
                       Headers2
               end,
@@ -405,16 +412,21 @@ convert_to(mc_amqp, #content{payload_fragments_rev = Payload} = Content, Env) ->
              Section ->
                  Section
          end,
-
     BodySections = case Type of
                        ?AMQP10_TYPE ->
                            amqp10_framing:decode_bin(
                              iolist_to_binary(lists:reverse(Payload)));
                        _ ->
                            [#'v1_0.data'{content = lists:reverse(Payload)}]
                    end,
+    Tail = case amqp10_section_header(?AMQP10_FOOTER, Headers) of
+               undefined ->
+                   BodySections;
+               #'v1_0.footer'{} = Footer ->
+                   BodySections ++ [Footer]
+           end,
 
-    Sections = [H, MA, P, AP | BodySections],
+    Sections = [H, MA, P, AP | Tail],
     mc_amqp:convert_from(mc_amqp, Sections, Env);
 convert_to(_TargetProto, _Content, _Env) ->
     not_implemented.