Auto-Login with guess

[2fd]

Automatically Login users as guess unless:

• is on desktop (?): keep the current behavior
• user has a previous session: use the previous session
• ff seamless_login_variant is disabled (decentraland/explorer-website/issues/374): keep the current behavior
• param show_wallet is 1 (https://github.com/decentraland/explorer-website/issues/375): prevent login and follow steps defined on the issue