currencyrate: expose get_median_rate and do conversion in front-end for currencyconvert.

diff --git a/plugins/currencyrate-plugin/src/main.rs b/plugins/currencyrate-plugin/src/main.rs
index 8dc85651..d0d3f475 100644
--- a/plugins/currencyrate-plugin/src/main.rs
+++ b/plugins/currencyrate-plugin/src/main.rs
@@ -10,11 +10,12 @@ use std::sync::Arc;
 use std::vec;
 use tokio::sync::Mutex;
 
-use crate::oracle::{BtcPriceOracle, Source, MSAT_PER_BTC};
+use crate::oracle::{BtcPriceOracle, Source};
 
 mod oracle;
 
 const DEFAULT_PROXY_PORT: u16 = 9050;
+const MSAT_PER_BTC: f64 = 1e11;
 
 #[derive(Debug, Clone)]
 pub struct SourceResult {
@@ -129,9 +130,9 @@ async fn currencyconvert(plugin: Plugin<PluginState>, args: Value) -> Result<Val
     let oracle = plugin.state().oracle.lock().await;
     oracle.currency_requested(&currency).await;
 
-    match oracle.convert(amount, &currency).await {
-        Ok(result) => Ok(json!({
-            "msat": result,
+    match oracle.get_median_rate(&currency).await {
+        Ok(rate) => Ok(json!({
+            "msat": (amount * MSAT_PER_BTC / rate).round() as u64,
         })),
         Err(e) => Err(anyhow!("Error converting currency: {e}")),
     }
diff --git a/plugins/currencyrate-plugin/src/oracle.rs b/plugins/currencyrate-plugin/src/oracle.rs
index 0098c943..7145c4ff 100644
--- a/plugins/currencyrate-plugin/src/oracle.rs
+++ b/plugins/currencyrate-plugin/src/oracle.rs
@@ -20,8 +20,6 @@ const DRIFT_THRESHOLD: f64 = 0.01;
 const INITIAL_BACKOFF: Duration = Duration::from_secs(30);
 const MAX_BACKOFF: Duration = Duration::from_secs(3_600);
 
-pub const MSAT_PER_BTC: f64 = 1e11;
-
 #[derive(Debug, Clone)]
 pub struct Source {
     name: String,
@@ -312,7 +310,7 @@ impl BtcPriceOracle {
         Ok(results)
     }
 
-    pub async fn convert(&self, amount: f64, currency: &str) -> Result<u64, anyhow::Error> {
+    pub async fn get_median_rate(&self, currency: &str) -> Result<f64, anyhow::Error> {
         let inner = self.inner.lock().await;
         let source_results = if let Some(currency_cache) = inner.currencies.get(currency) {
             let prices = currency_cache.fresh_prices();
@@ -328,8 +326,7 @@ impl BtcPriceOracle {
             self.get_all_rates(currency).await?
         };
 
-        let median_currency_per_btc = get_median_rate(source_results);
-        Ok((amount * MSAT_PER_BTC / median_currency_per_btc).round() as u64)
+        Ok(get_median(source_results))
     }
 
     async fn refresh_currency(&self, currency: &str) -> Result<(), anyhow::Error> {
@@ -528,7 +525,7 @@ impl BtcPriceOracle {
     }
 }
 
-fn get_median_rate(source_results: Vec<SourceResult>) -> f64 {
+fn get_median(source_results: Vec<SourceResult>) -> f64 {
     let mut prices: Vec<f64> = source_results.iter().map(|r| r.price).collect();
     prices.sort_by(|a, b| a.partial_cmp(b).unwrap());
     let mid = prices.len() / 2;