Record, show Project/Sub-Project Hierarchies

On internal records, the CNCF has segmented some of the larger projects in to separate projects and there is a natural hierarchical relationship that can easily be captured.

Current Examples on our internal records we have

Kubernetes is split into
- Kubernetes Steering Committee
- Kubernetes Maintainers (not tracking internally SIG based organization of the Kubernetes)

Istio is segmented as follows
- Steering Committee
- Technical Oversight Committee
- Working Group Leads
- Maintainers

Maintainer-d has modelled this idea in the project table in the database by having a parent project id col in a project record.

A Project is deemed a sub-project of another project if it is has parent_project_id (which of course must reference a project)

This means we could accomodate "complex" project hierarchies that projects use to self-organize.

Rules

- A Project can be the Parent Project of multiple Sub-Projects
- A Sub-Project can only have one Parent Project
- A parent project can be sub-project

So this would accomodate both simple and complex hierarchies presentable as a tree

Will use this issue to track

- presentation of project heierarchies on the web ui front-end, namely
- registration of a parent project relationship (updating a project's parentId field)
- presentation of a hierarchy in a tree
- api improvements and changes