Expose health status over RPC (#6274)

* Node-health to a separate crate.

* Initialize node_health outside of dapps.

* Expose health over RPC.

* Bring back 412 and fix JS.

* Add health to workspace and tests.

* Fix compilation without default features.

* Fix borked merge.

* Revert to generics to avoid virtual calls.

* Fix node-health tests.

* Add missing trailing comma.

dapps/src/api/mod.rs

@@ -18,8 +18,6 @@
 
 mod api;
 mod response;
-mod time;
 mod types;
 
 pub use self::api::RestApi;
-pub use self::time::TimeChecker;