v8: Rollback clear image cropper and grid

[bjarnef]

In Umbraco v8 with latest changes in v8/dev branch, when I select rollback and select an older version, but without clicking submit button (rollback), but just close the dialog and go back to the content tab the image cropper and grid no longer shows any values.

But when I refresh the page the values image cropper image and grid data are shown.

[PerplexDaniel]

Yes, excellent @bjarnef! I was about to make a new issue and PR with essentially the same but thought "let's see if someone else already did this" ;-)

This applies to all property editors that have their value stored as JSON, so it's quite a big deal.
It it still present in 8.6.1 and the latest v8/contrib.

@nul800sebastiaan Can we please merge the linked PR into v8 soon-ish? Mainly it's about this commit which does an angular.copy of the original property. There are 4 other commits in there with useful stuff but the core bug is fixed by just doing an angular.copy, which therefore could also be cherry-picked instead.

Full commit of @bjarnef with the fix is below (just to show it's tiny):

// copy existing properties, so it doesn't manipulate existing properties on page
oldProperty = angular.copy(oldProperty);
property = angular.copy(property);

Considering #7950 we would just have to change that to Utilities.copy instead and we're good to go.

[bjarnef]

Oh, it has been a while since I submitted that PR.. almost forgot about it 🙈

It seems Utilities.copy still use angular.copy() under the hood, but sure it would be great to use the utility function here instead.
https://github.com/umbraco/Umbraco-CMS/blob/v8/contrib/src/Umbraco.Web.UI.Client/src/utilities.js#L21

[nul800sebastiaan]

Fixed in #5792

[nul800sebastiaan]

Ah forgot to update to Utilities.copy - done in 9be4775