update show-inherit logic to match Umbraco Core logic and fix logic

[kmeilander]

No description provided.

[AlexanderWagner82]

This one works great on documentTypes but renders Image and Files un-editable (since they don't have any language). There's probably a better way to fix this but i Changed this line (inside $scope.propertyEditorDisabled) from

if (property.unlockInvariantValue)

to

if (property.unlockInvariantValue || $scope.content.contentTypeAlias == "Image" || $scope.content.contentTypeAlias == "File") {