feat(scope): add internal streams consistency checks
fix(change-detection): corrected adding group to sibling which had children
fix(WatchGroup): don't call reaction functions on removed WatchGroups
fix(scope): should not trigger assertions on fork
fix(block_factory): should not call attach when scope is destroyed
fix(block_factory): should not load template or call onShadowRoot when scope is destroyed
fix(scope): correctly handle canceled listeners bookkeeping