support custom fields

[stmeissner]

For now it is not possible to import categories enhanced with custom fields.
Would be nice to have this supported.

[mmoelli]

@PhilippSpo Small brain teaser in between

We need this feature for Go live of a project. Any idea about effort regarding this topic?

Maybe @ahalberkamp can give more info regarding which kind of custom field types (boolean, string, etc.) needs to be supported for now.

[ahalberkamp]

@PhilippSpo We need a "active" boolean-flag on each category, so that we can easily show or hide categories by setting this flag properly. To fulfil this requirement, I have created the custom category, which contains this Flag. Now I need a possibility to import this flag properly.

[PhilippSpo]

Alright I talked to @ahalberkamp and verified what is actually needed here.
@mmoelli I think adding support for updating custom fields here is not hard, but the user needs to make sure that his category as a custom type that actually contains the custom field that he specified in the import. What if there are new categories in the sync that do not have a custom type yet? Does this mean we also need to add support for setting a custom type for categories here?