[SyncManager] Unify LocalStorage access

[rfc2822]

• Move local storage classes package: .resource → .resource.local
• Make all local storage classes non-blocking / suspending
• (Or at least wrap LocalStorage access in SyncManager withContext(ioDispatcher) and remove generic dispatcher)
• Make sure all Local* classes marked as suspend are actually suspending
• Flows in synctools: verify where the .flowOn() belongs to. Probably: synctools can generate Flow<>, but flowOn(ioDispatcher) belongs to core/Local*.