[MM-58492][MM-58523] Fixed some access control bugs around archived channels by replacing the permission check with HasPermissionToReadChannel (#27409)

* [MM-58492][MM-58523] Fixed some access control bugs around archived channels by replacing the permission check with HasPermissionToReadChannel

* Fix lint, add ChannelId to uploads

* Fix MMCTL tests and remove unnecessary check for the error message that doesn't work anyways

* Include channel map for getting flagged posts

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

server/channels/api4/post_test.go

@@ -1831,7 +1831,7 @@ func TestGetPostsForChannel(t *testing.T) {
 
 	_, resp, err := client.GetPostsForChannel(context.Background(), model.NewId(), 0, 60, "", false, false)
 	require.Error(t, err)
-	CheckForbiddenStatus(t, resp)
+	CheckNotFoundStatus(t, resp)
 
 	client.Logout(context.Background())
 	_, resp, err = client.GetPostsForChannel(context.Background(), model.NewId(), 0, 60, "", false, false)