feat: Better activity and complete states for approval and sign tx buttons

[0xTomDaniel]

Abstract

• The Approve and Sign Transaction buttons don't have activity indicators while a status update is pending.
• The Sign Transaction button doesn't is still clickable after signing has complete. The button should be replaced by some sort of success indication icon.

[varelaseb]

also include link to block explorer for the tx one signed

[0xTomDaniel]

@dev-coda what's blocking this?

[varelaseb]

@dev-coda please review