[MM-49989] Pass a context.Context to Client4 methods (#22922)

* Migrate all method in model/client4.go to accept a context.Context

* Fix th.*Client

* Fix remaining issues

* Empty commit to triger CI

* Fix test

* Add cancellation test

* Test that returned error is context.Canceled

* Fix bad merge

* Update mmctl code

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/saml_test.go

@@ -4,6 +4,7 @@
 package api4
 
 import (
+	"context"
 	"net/http"
 	"testing"
 
@@ -18,7 +19,7 @@ func TestGetSamlMetadata(t *testing.T) {
 	defer th.TearDown()
 	client := th.Client
 
-	_, resp, err := client.GetSamlMetadata()
+	_, resp, err := client.GetSamlMetadata(context.Background())
 	require.Error(t, err)
 	CheckNotImplementedStatus(t, resp)
 
@@ -65,11 +66,11 @@ func TestSamlResetId(t *testing.T) {
 	})
 	require.Nil(t, appErr)
 
-	_, resp, err := th.Client.ResetSamlAuthDataToEmail(false, false, nil)
+	_, resp, err := th.Client.ResetSamlAuthDataToEmail(context.Background(), false, false, nil)
 	require.Error(t, err)
 	CheckForbiddenStatus(t, resp)
 
-	numAffected, resp, err := th.SystemAdminClient.ResetSamlAuthDataToEmail(false, false, nil)
+	numAffected, resp, err := th.SystemAdminClient.ResetSamlAuthDataToEmail(context.Background(), false, false, nil)
 	require.NoError(t, err)
 	CheckOKStatus(t, resp)
 	require.Equal(t, int64(1), numAffected)