Label.UserLocalizedLabel can be null in some cases

[FixRM]

Hello @scottdevelop1, As it turns out, UserLocalizedLabel is not always available, so we have null reference here: https://github.com/scottdurow/SparkleXrm/blob/1fe0444a9466c4f48cb061c4f06bb59db3aae201/spkl/CrmSvcUtilFilteringService/FilteringService.cs#L62

We are still investigating, how to reproduce the issue, but I believe it's happening when base language of source system doesn't feat target's.

We have hotfix, but before creating a PR I want to clear up the idea behind this code. As I see, most overrides are made for filtering purposes, except things related to option sets. Why does it had to have to be part of the spkl? I mean duplicates are bad, I guess, but why does it should be fixed as part of generation? Option can be renamed of deleted and this changes will lead to build errors. Why not duplicates, bad names, or lost local strings?

p.s. For me, optionsets are broken by design :) They always should be int? properties.