[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/channel_test.go

@@ -2916,7 +2916,7 @@ func TestGetPinnedPosts(t *testing.T) {
 
 	_, resp, err = client.GetPinnedPosts(context.Background(), GenerateTestID(), "")
 	require.Error(t, err)
-	CheckForbiddenStatus(t, resp)
+	CheckNotFoundStatus(t, resp)
 
 	_, resp, err = client.GetPinnedPosts(context.Background(), "junk", "")
 	require.Error(t, err)