Also use PureDatagridRow to speed up SongDatagrid

ui/src/common/useTraceUpdate.js

@@ -0,0 +1,17 @@
+import { useRef, useEffect } from 'react'
+
+export function useTraceUpdate(props) {
+  const prev = useRef(props)
+  useEffect(() => {
+    const changedProps = Object.entries(props).reduce((ps, [k, v]) => {
+      if (prev.current[k] !== v) {
+        ps[k] = [prev.current[k], v]
+      }
+      return ps
+    }, {})
+    if (Object.keys(changedProps).length > 0) {
+      console.log('Changed props:', changedProps)
+    }
+    prev.current = props
+  })
+}