Add parent relationship to categories

[poliquinp]

Based on the list of new categories, add a parent relationship capability to categories.

[jpmurray]

Might already be in your pipeline, but I think we might have to plan in advance that we might have multiple child categories.

[poliquinp]

Might already be in your pipeline, but I think we might have to plan in advance that we might have multiple child categories.

Task is on hold at the moment on our side. But our main idea was to create a "parent ID" where 0 is top level so we could easily do multi-level.

[jpmurray]

That's what I was seeing too! 👍

[jpmurray]

For the records: added in PR #43