Use Vue's new effect scopes to improve efficiency

[samatechtw]

Vue 3.2 introduces a new effect scope API for library authors. We can use it to help improve the vue3-eth API - currently each page needs to call reconnectWallet on mount, and there isn't a great way to clean up memory if no longer needed. With an effect scope it should be easy to do initialization once and make it available across the SPA.

Tasks

• Upgrade to Vue 3.2
• Use effect scope to improve reconnect/disconnect API and performance