Add Direct Link for GOG Giveaways

[SobinSiril]

Is your feature request related to a problem? Please describe.

The usual link to the game has to go through 2 or more clicks to get to the actual giveaway.

Describe the solution you'd like

It would be nice if GOG giveaways also had this direct link to the giveaway claim : https://www.gog.com/giveaway/claim

Anything else?

Although not that necessary, this is the direct link to page where you can disable the marketing options that are automatically activated when claiming the free game : https://www.gog.com/account/settings/subscriptions