Repeatable strings inside DocTypeGridEditors are not deserialized correcltly.

[KevinJump]

If you have a Repeatable String property inside a document type that you are using inside a DocTypeGrid Editor then the values are not created when you import to a new site.

this is because the default behavior of the doctypegrid editor mapper is to escape the json values of any nested json properties (this is how we do it for nestedcontent, content blocks etc) however for the doctype grid editor we should not do this :(

[KevinJump]

Fix for this, is to not encode - but we also need to ensure that any nested nested values are not encoded,

so for example if there is a nested content block inside the doctypegrid editor and that contains yet more nested json values, we need to expand them but only when in the dcotype grid editor and not when we are inside other editors.

[KevinJump]

re-open Also need fix for v8 branch