Allow disabling object merge behavior

[mrclay]

Our team has been bitten many times by the quirky merge behavior:

obj.set('foo', {one: 1, two: { a: 'a', b: 'b' }});
await obj.save(null);

obj.set('foo', {two: { b: 'b' }});
await obj.save(null);

console.log(obj.get('foo')); // { one: 1, two: { b: 'b' }}

First-level keys in attribute objects cannot be removed, only set to null. We have to completely unset('foo'), save, and re-set it to be assured it has the exected value.

This behavior isn't documented in Object.set.

[dplewis]

Is this for Postgres? What version of Parse-Server are you using? I believe this has been fixed.

#5242

[mrclay]

parse-server 2.8.1 on postgres, so looks like we'll have to get to 3.x. Thanks.

[dplewis]

No problem! A lot of PG improvements made.

Can you comment on #5336?