* Split out ReadRequest and ReadResponse state service enums
* Simplify RPC test vectors
* Split state requests into Request and ReadRequest
* Make zebra-rpc use the new state ReadRequest
* Add request metrics to ReadStateService
Add a field to distinguish StateService and ReadStateService metrics.
Add missing StateService request metrics.
* Refactor state transaction lookup so it can be shared between services
* Implement ReadState Request::Transaction
* Revert "Drop the Chain watch channel lock before accessing the finalized state"
This reverts commit 8870944d1323fc31e2d009b9938623de6fcbe50f.
* Add a WatchReceiver wrapper that always clones the borrowed watch data
This avoids deadlocks, by holding the read lock for as short a time as possible.
* Drop the shared Arc<Chain>s as quickly as possible
This reduces memory usage.
* Make read::block more flexible, by accepting any AsRef<Chain>
* Make the block method docs consistent
* Avoid livelocks by explicitly dropping the borrow after the clone
* Use the read-only state service for RPCs
* Refactor non-finalized block lookup into Chain
* Implement the read-only state block request
* Drop the Chain watch channel lock before accessing the finalized state
teor