[Tracked with Parent Issue] Allow same email to be invited to multiple accounts

This task is currently tracked with a parent Issue. For more details and latest progress, please visit: https://simplebase.featurebase.app/submissions/654a486f7130c8704fd3cba0

Looks like once you invite a team member to 1 account, the invite proces will not allow that same email/user to be part of a 2nd account. Please allow the same email teammate to be part of multiple KB accounts.