Add Object Storage and Service Catalog categories to Scalability

Proposal

This MR proposes that groupscalability take formal ownership of Object Storage and the Service Catalog.

groupscalability have acted as owners of Object Storage for the last year or so. It has been debated whether we should formally add it as a category, as it's often seen as more of a system component. However, the absence of doing so has made it tricky for people to find the correct owner or to easily direct issues (example #14470).

Adding Service Catalog at the same time, for similar reasons. groupscalability have agreed to take ownership here: gitlab-com/gl-infra&892 (comment 1253939329).

Approvals

Merge requests with changes to stages and groups and significant changes to categories need to be created, approved, and/or merged by each of the below:

• Chief Product Officer @david
• The Product Director relevant to the affected Section(s) @marin
• The Engineering Director relevant to the affected Section(s) @fzimmer
• Director of Product Design @vkarnes

The following people need to be on the merge request so they stay informed:

• Vice President of Development @clefelhocz1
• Vice President of Quality @meks
• Vice President of User Experience @clenneville
• The Product Marketing Manager relevant to the stage group(s)
• Director of Technical Writing @susantacker

After Approvals and Merge

• Create an issue in the triage-ops project to update GitLab Bot automation:
  • for Category change
  • for Stage or Group change
• Mention the product group Technical Writer to update the documentation metadata
• Share MR in #product, #development, and relevant #s_, #g_, and #f_ slack channels