feat: IBC Eureka support on cosmwasm ibc libraries (#320)

Author: keyleu

contracts/libraries/generic-ibc-transfer/README.md

@@ -48,6 +48,8 @@ struct LibraryConfig {
   remote_chain_info: RemoteChainInfo,
   // Denom map for the Packet-Forwarding Middleware, to perform a multi-hop transfer.
   denom_to_pfm_map: BTreeMap<String, PacketForwardMiddlewareConfig>,
+  // Configuration used for IBC Eureka transfers
+  eureka_config: Option<EurekaConfig>,
 }
 
 // Defines the amount to be transferred, either a fixed amount or the whole available balance.
@@ -73,8 +75,24 @@ struct PacketForwardMiddlewareConfig {
   local_to_hop_chain_channel_id: String,
   // Channel ID from the intermediate to the destination chain
   hop_to_destination_chain_channel_id: String,
-  // Temporary receiver address on the intermediate chain. Typically this is set to an invalid address so the entire transaction will revert if the forwarding fails. If not 
+  // Temporary receiver address on the intermediate chain. Typically this is set to an invalid address so the entire transaction will revert if the forwarding fails. If not
   // provided it's set to "pfm"
   hop_chain_receiver_address: Option<String>,
 }
+
+// Configuration for IBC Eureka transfers
+pub struct EurekaConfig {
+    /// The address of the contract on intermediate chain that will receive the callback.
+    pub callback_contract: String,
+    /// The address of the contract on intermediate chain that will trigger the actions, in this case the Eureka transfer.
+    pub action_contract: String,
+    /// Recover address on intermediate chain in case the transfer fails
+    pub recover_address: String,
+    /// Source channel on the intermediate chain (e.g. "08-wasm-1369")
+    pub source_channel: String,
+    /// Optional memo for the Eureka transfer triggered by the contract. Not used right now but could eventually be used.
+    pub memo: Option<String>,
+    /// Timeout in seconds to be used for the Eureka transfer. For reference, Skip Go uses 12 hours (43200). If not passed we will use that default value
+    pub timeout: Option<u64>,
+}
 ```