Show loading state before displaying unlocking tokens

[Soleone]

Problem

There are edge cases where the lookup of the NFTs in the user's wallet can take longer than expected, particularly if the wallet contains thousands of results, or the blockchain provider is just generally slow.

In that case the current behavior is that the connect wallet button displays the connected address already, but the tokengate card still displays the required tokens instead of the unlocking tokens.

Suggestion

Introduce a loading state that will be replaced by the unlocked state once the unlocking tokens are available.