feat(kgm): expose db decrypt function

um_wasm/src/exports/kgm.rs

@@ -1,4 +1,4 @@
-use umc_kgm::{header::Header, Decipher};
+use umc_kgm::{decrypt_db, header::Header, Decipher};
 use wasm_bindgen::prelude::wasm_bindgen;
 use wasm_bindgen::JsError;
 
@@ -57,4 +57,10 @@ impl JsKuGou {
     pub fn decrypt(&self, buffer: &mut [u8], offset: usize) {
         self.0.decrypt(buffer, offset)
     }
+
+    /// Decrypt Kugou PC client db.
+    #[wasm_bindgen(js_name=decryptDatabase)]
+    pub fn decrypt_db(database: &mut [u8]) -> Result<(), JsError> {
+        decrypt_db(database).map_err(JsError::from)
+    }
 }