Link a Projects as a component of another project

### Current Behavior

User must manually calculate vulnerabilities of all projects being deployed

### Proposed Behavior

I wish for the "add component" button to now have a drop-down of 2 options:

- Component
- Project

When a user selects the project option they are provided UI to select a project and version which already exists in dependency track.

The way my releases work i have multiple micro-services which are bundled together as part of a build pipeline to form 1 installer for the end user.
With the proposed approach i could select a "project" which represents my installed and see all the projects which are contributing to that installer and have install visibility into the health of that release.

Alternative option would be to allow multiple parent projects

### Checklist

- [X] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [X] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this enhancement was already requested