Export doesn't include $metadata or $themes

[six7]

Our Export currently is missing our $themes and $metadata properties, this is different per implementation:

Single file export is missing $themes object

When you export to a single file it seems we do not include the $themes object, which we should.
We should also include the $metadata object.

Multi file export is missing $metadata file

When you export to a folder the created folder doesn't include the $metadata file (which is useful as we store tokenSetOrder in there, so custom order of users token sets is preserved).
This one does include the $themes object, though.

What needs to change?

Single file export: Should get both $themes and $metadata object
Multi file export: Should get the $themes object
Import: We should make sure that Importing these files/folders respects these properties.