feat: refactor middleware stack (#1398)

* feat(middleware-stack): refactor middleware stack implementation and interface

* feat: update dedendents with updated middleware interface

* feat(middleware-stack): make middleware stack a pluggable, address feedbacks

BREAKING CHANGE: addRelativeTo() now doesn't require step in options. The middleware will be injected to the same step as the toMiddleware

Author: AllanZhengYP