add loom jdbc test

sample/src/LoomTest.kt

@@ -0,0 +1,20 @@
+import com.sun.net.httpserver.HttpServer
+import klite.Config
+import klite.jdbc.PooledDataSource
+import klite.jdbc.query
+import java.net.InetSocketAddress
+import java.util.concurrent.Executors
+
+fun main() {
+  Config.useEnvFile()
+  val db = PooledDataSource(maxSize = 100)
+  HttpServer.create(InetSocketAddress(8080), 10).apply {
+    executor = Executors.newThreadPerTaskExecutor(Thread.ofVirtual().name("req-", 1).factory())
+    createContext("/hello") { e ->
+      val dbTime = db.query("select pg_sleep(1), clock_timestamp()") { getString(2) }.first()
+      e.sendResponseHeaders(200, 0)
+      e.responseBody.writer().use { it.write("$dbTime, ${Thread.currentThread().name} ${Thread.currentCarrierThread().name}\n") }
+    }
+    start()
+  }
+}