frontend: introduces propsAreEqual function passed to React.memo to reduce re-rendering

This function accepts the component’s previous props, and its new props.
It should return true if the old and new props are equal: that is, if the component will
render the same output and behave in the same way with the new props as with the old.
I need to use this function as state objects that are passed as props will always have different references.

frontend/src/utils/propsAreEqual.ts

@@ -0,0 +1,17 @@
+import deepEqual from "deep-equal";
+
+export const propsAreEqual = <T extends object>(
+  prevProps: T,
+  nextProps: T,
+): boolean => {
+  for (const key in nextProps) {
+    if (typeof nextProps[key] === "object") {
+      if (!deepEqual(prevProps[key], nextProps[key])) {
+        return false;
+      }
+    } else if (!Object.is(prevProps[key], nextProps[key])) {
+      return false;
+    }
+  }
+  return true;
+};