Add support for Topic Hierachy and payload schema generation to Project Nodes

### Description

> Also curious if there are any plans to show project node hierarchies in the "broker" section of FlowFuse... having visibility to all of the project nodes being used in one place would be super helpful/useful.

https://app-eu1.hubspot.com/help-desk/26586079/view/233410279/ticket/73648559300/thread/9824402674#live-chat

### Which customers would this be available to

Team + Enterprise Tiers (EE)

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate

Start by reviewing the Project Nodes implementation and the broker section referenced in the issue, then trace how topic information and payload schemas are currently represented. Clarify the expected hierarchy and schema-generation behavior for Team and Enterprise tiers. Done means Project Nodes support both capabilities and the broker section provides the requested visibility.

Written by the indexing model from the issue text.