Add FiatAPI methods to Liquid SDK (#331)

* Add FiatAPI methods to Liquid SDK

* Add mirrored structs of fiat crate on Dart bindings

* Re-generate bindings

* Fix sdk-common imports

* Avoid using hardcoded Breez Server URL, re-use sdk-common constant

* Update Cargo.lock

---------

Co-authored-by: Erdem Yerebasmaz <erdem@yerebasmaz.com>

cli/src/commands.rs

@@ -106,6 +106,10 @@ pub(crate) enum Command {
         /// LNURL-auth endpoint
         lnurl: String,
     },
+    /// List fiat currencies
+    ListFiat {},
+    /// Fetch available fiat rates
+    FetchFiatRates {},
 }
 
 #[derive(Helper, Completer, Hinter, Validator)]
@@ -376,6 +380,14 @@ pub(crate) async fn handle_command(
 
             command_result!(res)
         }
+        Command::FetchFiatRates {} => {
+            let res = sdk.fetch_fiat_rates().await?;
+            command_result!(res)
+        }
+        Command::ListFiat {} => {
+            let res = sdk.list_fiat_currencies().await?;
+            command_result!(res)
+        }
     })
 }