introducing PBKD support in keys amd generation server

src/commonTest/kotlin/RingTest.kt

@@ -70,6 +70,7 @@ class RingTest {
         println(r1.findKey<EncryptingKey>(sk.id))
         println(sk)
         assertTrue { sk.publicKey.toUniversalKey() == r1.findKey<EncryptingKey>(sk.id) }
+        assertTrue { sk.publicKey.toUniversalKey() == r1.keyByTag<EncryptingKey>("foo") }
     }
 
     @Test