[ios] add file for project.
Move WaitableBool from Async to Thread package.
[Thread] Add LockGuard class, change UniqueLock from function to class.
- Modify all files which use UniqueLock.
[Async] Implement AnyEventDispatcher.
- But event ID range checking is no supported yet.
- Rename Add/RemoveQueue() to Link/UnlinkTarget()
Fix: Assersion can only be tested in Debug built.