FIX: Emoji uploader not using on uppy upload (PR #14958)

When uploading emoji with the new uppy upload mixin, we were not sending the name of the emoji in the payload, or more accurately uppy was already using the file name as the name value and we were not overriding it from data. This commit changes the behaviour for single files uploaded via the uppy upload mixin, by merging the file’s meta object with from the parent component.


Docs on isEmpty:

Verifies that a value is null or undefined, an empty string, or an empty array. isEmpty({}); // false

Wow that’s what I get for making assumptions! Will fix

Now I’m wondering: is Object.keys( necessary? Imo even part isn’t strictly required (deepMerge() does value || {})

Ah I didn’t realise deepMerge already did it’s own fallback, will change and see

@CvX yeah that works even with set to null