Redesign Go-to step sidebar connection

When users select a step's step-type as Go-To, the new sidebar will present a dropdown for the user to easily search and select the step they want to conenct this go-to step with.

Right now users have to try to connect a go-to step using a connector, and when two steps are far apart it's very tedious to configure the go-to step. Now it will be much easier.