List all GoogleCloudPlatform orbit artifacts

[elharo]

This is basically a list of Maven coordinates for things in cloud-oss-bom. However we eventually want to expand it with

• artifact
• repo
• owners
• list of dependency changes needed

Furthermore, it's not necessarily tied to specific versions as the BOM is.

1. Decide where we'll put this list. (Trix? XML in repo?) Keep in mind that there will be a lot of subdetail for each item. It's not a flat list. Do we need/want it to be machine consumable?

2. Build the list with full Maven coordinates