feat: server health call implementation

[Vovke]

Resolves #60

[Vovke]

thats initial state, all rpcs initialized as Critical until proven differently

[Vovke]

before we try to connect we set rpc health degraded

[Vovke]

Ok if successfully connected

[Vovke]

If all RPCs are OK, ServerHealth is OK,
if not all OK but some, ServerHealth is Degraded
in none are OK, ServerHealth is Critical

[fluiderson]

You should never use sync locking primitives in async code. This thing might lock an entire async runtime and thus the program if you accidentally put an awaiting point in a code interval wherein the lock is held.

[Vovke]

Addressed

[fluiderson]

Suggested change

connected_rpcs: Arc<RwLock<Vec<RpcInfo>>>,

@Slesarew decided to use channels instead of locks everywhere. With this approach, all variables should be declared in an initialization function, not in a struct, like there:

Kalatori-backend/src/chain/mod.rs

Lines 56 to 58 in fe135a3

	let mut watch_chain = HashMap::new();
	let mut currency_map = HashMap::new();

Kalatori-backend/src/state.rs

Lines 65 to 76 in fe135a3

	let chain_manager = chain_manager.await.map_err(|_| Error::Fatal)?;
	let db_wakeup = db.clone();
	let chain_manager_wakeup = chain_manager.clone();
	let currencies = HashMap::new();
	let mut state = StateData {
	currencies,
	recipient,
	server_info,
	db,
	chain_manager,
	signer,
	};

I'm against this approach, and plan to refactor it in locks later, but for now I suggest to abide by at least one approach for every module instead of mixing them.

[Vovke]

Addressed

[fluiderson]

✅