Update notification/auto-update for Finch

[KevinLiAWS]

What is the problem you're trying to solve?. Currently, users have to check Finch release notes or blindly run brew command to detect if there is a new version of Finch. Have a notification or auto update can help users be aware of new version release.

Describe the feature you'd like When the user execute some Finch commands, or if Finch has GUI, it can show new version available notification.