[BENS] Fix coin encoding and patch bug (#741)

* Fix coin encoding and patch bug

* Fix conversion

* Fix rsk checksummedhex

blockscout-ens/bens-logic/src/coin_type/coin.rs

@@ -0,0 +1,55 @@
+use super::encoding::Encoding;
+use lazy_static::lazy_static;
+use serde::{Deserialize, Serialize};
+
+const COIN_TYPES_JSON: &str = include_str!("coin_types.json");
+
+lazy_static! {
+    pub static ref COINS_TYPES: Vec<Coin> =
+        serde_json::from_str(COIN_TYPES_JSON).expect("coin_types.json should be valid");
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Coin {
+    pub name: String,
+    pub coin_type: String,
+    pub encoding: Option<Encoding>,
+}
+
+impl Coin {
+    pub fn unknown_type(coin_type: String) -> Self {
+        Self {
+            name: format!("unknown coin ({coin_type})"),
+            coin_type,
+            encoding: None,
+        }
+    }
+
+    pub fn find_or_unknown(coin_type: &str) -> Self {
+        COINS_TYPES
+            .iter()
+            .find(|c| c.coin_type == coin_type)
+            .cloned()
+            .unwrap_or_else(|| Coin::unknown_type(coin_type.to_string()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        for (coin_type, expected_name) in &[
+            ("0", "BTC"),
+            ("60", "ETH"),
+            ("137", "RSK"),
+            ("2147483785", "MATIC"),
+            ("9999999999", "unknown coin (9999999999)"),
+        ] {
+            let maybe_coin = Coin::find_or_unknown(coin_type);
+            assert_eq!(maybe_coin.name.to_string(), expected_name.to_string())
+        }
+    }
+}