Revert "[MODIFY] change webworker usage"
Revert "[MODIFY] use WebWorker for purgeBlockedUsers"

This reverts commit 31146cd9bc185b7fb7dfd297be2bf56028d73c32.
This reverts commit bf616d7d986ad0dd6a4571e11ac15988d022a41d.
[MODIFY] use Set to store blocked and muted users in tweetmanager