Function normalize_spot_symbol 

pub fn normalize_spot_symbol(symbol: &str) -> String

Normalizes a Kraken spot wsname symbol to the form accepted by WS v2.

Kraken’s REST API wsname field is supposed to be the WS-ready symbol, but some codes are stale and differ from what WS v2 actually accepts. This function applies all known renames so that instruments and subscriptions use consistent symbols. Renames are applied to both the base and quote leg of the pair.