Support new data governance feature

[randycoulman]

And here comes the magic to handle our new datagovernance feature. Please adjust this with the same logic from here:
https://github.com/configcat/python-sdk/blob/master/configcatclient/configfetcher.py#L74

Originally posted by @laliconfigcat in #2 (comment)

[igorescobar]

Maybe start this one only after migrating to the v5 format, right? #18

[laliconfigcat]

Yes, these settings will only be available in v5

[igorescobar]

Just to give you some progress on this. The code is mostly done but I'm still not sure about the current implementation tho (design-wise) and I'm still trying to figure it out the best way to test this. I haven't had a lot of time recently and that's why it is taking more time. I hope to get this done today.