Allow to pass a full array in partial write

[reczkok]

Currently, partialWrite expects:

public readonly '~reprPartial'!: {
    idx: number;
    value: InferPartial<TElement>;
  }[];

This means we need to pass an array od objects which can be inconvenient if the array is nested and someone does not want to write granularly to it. Currently it would require converting the array to an array of objects. We should allow to pass a full array just like in normal write.