Revert "Implement _.pick to simplify serialization (#763)" (#823)

Reason: Performance

- 40x slower slot serialisation using randomised data
- Overall 2-3x slower `graph.serialize()` on a 600 node graph

This reverts commit 77465113cd.

src/utils/object.ts

@@ -3,21 +3,3 @@ export function omitBy<T extends object>(obj: T, predicate: (value: any) => bool
     Object.entries(obj).filter(([_key, value]) => !predicate(value)),
   ) as Partial<T>
 }
-
-/**
- * Creates an object composed of the picked object properties.
- * Similar to lodash's pick function.
- * @param obj The source object
- * @param keys The property names to pick
- * @returns A new object with just the picked properties
- */
-export function pick<T extends object, K extends keyof T>(obj: T, keys: K[]): Pick<T, K> {
-  // Assertion: Required to avoid verbose runtime guards
-  const picked = {} as Pick<T, K>
-  for (const key of keys) {
-    if (key in obj) {
-      picked[key] = obj[key]
-    }
-  }
-  return picked
-}