MM-11272 Add OpenGraph and image dimension metadata to posts (#9313)

* Move OpenGraph code into its own file

* Move OpenGraph image proxying to app layer

* Move test file code out of api4 package

* MM-11272 Add OpenGraph and image dimension metadata to posts

api4/team_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/mattermost/mattermost-server/model"
 	"github.com/mattermost/mattermost-server/services/mailservice"
 	"github.com/mattermost/mattermost-server/utils"
+	"github.com/mattermost/mattermost-server/utils/testutils"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -1813,7 +1814,7 @@ func TestImportTeam(t *testing.T) {
 	t.Run("ImportTeam", func(t *testing.T) {
 		var data []byte
 		var err error
-		data, err = readTestFile("Fake_Team_Import.zip")
+		data, err = testutils.ReadTestFile("Fake_Team_Import.zip")
 		if err != nil && len(data) == 0 {
 			t.Fatal("Error while reading the test file.")
 		}
@@ -1874,7 +1875,7 @@ func TestImportTeam(t *testing.T) {
 	t.Run("WrongPermission", func(t *testing.T) {
 		var data []byte
 		var err error
-		data, err = readTestFile("Fake_Team_Import.zip")
+		data, err = testutils.ReadTestFile("Fake_Team_Import.zip")
 		if err != nil && len(data) == 0 {
 			t.Fatal("Error while reading the test file.")
 		}
@@ -2029,7 +2030,7 @@ func TestSetTeamIcon(t *testing.T) {
 	Client := th.Client
 	team := th.BasicTeam
 
-	data, err := readTestFile("test.png")
+	data, err := testutils.ReadTestFile("test.png")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -2109,7 +2110,7 @@ func TestRemoveTeamIcon(t *testing.T) {
 	team := th.BasicTeam
 
 	th.LoginTeamAdmin()
-	data, _ := readTestFile("test.png")
+	data, _ := testutils.ReadTestFile("test.png")
 	Client.SetTeamIcon(team.Id, data)
 
 	_, resp := Client.RemoveTeamIcon(team.Id)