Move sql store code into store/sqlstore package (#7502)

* move sql store code into store/sqlstore package

* move non-sql constants back up to store

* fix api test

* derp

store/sqlstore/system_store_test.go

@@ -0,0 +1,57 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package sqlstore
+
+import (
+	"testing"
+
+	"github.com/mattermost/mattermost-server/model"
+"github.com/mattermost/mattermost-server/store"
+)
+
+func TestSqlSystemStore(t *testing.T) {
+	ss := Setup()
+
+	system := &model.System{Name: model.NewId(), Value: "value"}
+	store.Must(ss.System().Save(system))
+
+	result := <-ss.System().Get()
+	systems := result.Data.(model.StringMap)
+
+	if systems[system.Name] != system.Value {
+		t.Fatal()
+	}
+
+	system.Value = "value2"
+	store.Must(ss.System().Update(system))
+
+	result2 := <-ss.System().Get()
+	systems2 := result2.Data.(model.StringMap)
+
+	if systems2[system.Name] != system.Value {
+		t.Fatal()
+	}
+
+	result3 := <-ss.System().GetByName(system.Name)
+	rsystem := result3.Data.(*model.System)
+	if rsystem.Value != system.Value {
+		t.Fatal()
+	}
+}
+
+func TestSqlSystemStoreSaveOrUpdate(t *testing.T) {
+	ss := Setup()
+
+	system := &model.System{Name: model.NewId(), Value: "value"}
+
+	if err := (<-ss.System().SaveOrUpdate(system)).Err; err != nil {
+		t.Fatal(err)
+	}
+
+	system.Value = "value2"
+
+	if r := <-ss.System().SaveOrUpdate(system); r.Err != nil {
+		t.Fatal(r.Err)
+	}
+}