[#74] apemanager: Generate protobufs for apemanager service

* Generate protobufs.
* Make marshallers, unmarshallers, json-encoders etc.
* Create message encoding/decoding unit-tests.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

apemanager/status_test.go

@@ -0,0 +1,30 @@
+package apemanager_test
+
+import (
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/apemanager"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/status"
+	statustest "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/status/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestStatusCodes(t *testing.T) {
+	statustest.TestCodes(t, apemanager.LocalizeFailStatus, apemanager.GlobalizeFail,
+		apemanager.StatusAPEManagerAccessDenied, 5120,
+	)
+}
+
+func TestAccessDeniedDesc(t *testing.T) {
+	var st status.Status
+
+	require.Empty(t, apemanager.ReadAccessDeniedDesc(st))
+
+	const desc = "some description"
+
+	apemanager.WriteAccessDeniedDesc(&st, desc)
+	require.Equal(t, desc, apemanager.ReadAccessDeniedDesc(st))
+
+	apemanager.WriteAccessDeniedDesc(&st, desc+"1")
+	require.Equal(t, desc+"1", apemanager.ReadAccessDeniedDesc(st))
+}