Backend: Remove `rootNamespace` field on `Catalog::ResourceType`

Problem

The MR !135017 (merged) updated Ci::Catalog::ResourcesResolver to return all projects visible to the current user in the Global Catalog. However, it did not account for the rootNamespace field, which will now be nil in cases where the current user can view a catalog resource but cannot view its root namespace. The frontend needs the root namespace in order to construct the full resource path. Ref:

• !135017 (comment 1634337904)
• !135017 (comment 1634321110)

In light of this problem, we are going change the approach for how FE renders the Catalog resource breadcrumb paths per #430791 (comment 1641658966). Instead of utilizing rootNamespace, we should use the Catalog Resource's webPath field.

Proposal

After the FE counterpart issue is complete (#431497 (closed)), we will no longer need the rootNamespace field and it can be removed.

Implementation

Group	Issue	Link
frontend	Frontend: Render the Catalog Resource breadcrum... (#431497 - closed)	#431497 (closed)
backend	Backend: Remove `rootNamespace` field on `Catal... (#430791 - closed)	👈 You are here