goimports (#16640)

* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w`

* added goimports lint check to .golangci.yml

* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w` for a corner case

* make app-layers, *-mocks and store-layers for ci check

Co-authored-by: Mahmudul Haque <mahmudulhaque@protonmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/searchlayer/channel_layer.go

@@ -4,11 +4,12 @@
 package searchlayer
 
 import (
+	"github.com/pkg/errors"
+
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/services/searchengine"
 	"github.com/mattermost/mattermost-server/v5/store"
-	"github.com/pkg/errors"
 )
 
 type SearchChannelStore struct {

store/searchlayer/post_layer.go

@@ -4,11 +4,12 @@
 package searchlayer
 
 import (
+	"github.com/pkg/errors"
+
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/services/searchengine"
 	"github.com/mattermost/mattermost-server/v5/store"
-	"github.com/pkg/errors"
 )
 
 type SearchPostStore struct {

store/searchlayer/user_layer.go

@@ -6,11 +6,12 @@ package searchlayer
 import (
 	"strings"
 
+	"github.com/pkg/errors"
+
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/services/searchengine"
 	"github.com/mattermost/mattermost-server/v5/store"
-	"github.com/pkg/errors"
 )
 
 type SearchUserStore struct {

store/searchlayer/utils.go

@@ -3,7 +3,9 @@
 
 package searchlayer
 
-import "strings"
+import (
+	"strings"
+)
 
 func sanitizeSearchTerm(term string) string {
 	return strings.TrimLeft(term, "@")