Marketplace entries in Eclipse project page create bogus URL
## Summary
The URLs that can be set in the Eclipse project page lead to invalid URLs. For example, this is configured for the WindowBuilder project:

From what I understand, this should create two buttons, one labeled "Latest Version", linking to https://marketplace.eclipse.org/content/windowbuilder and one labeled "Nightly Version", linking to https://marketplace.eclipse.org/content/windowbuilder-nightly-build.
However, this only produces the bogus URL https://marketplace.eclipse.org/content/windowbuilder,%20Latest%20Version,%20https://marketplace.eclipse.org/content/windowbuilder-nightly-build,%20Nightly%20Version.
Note that this issue not only exists for WindowBuilder, but other projects have the same problem, which makes me believe that this is either a gross misunderstanding on how this entry is supposed to work, or a general issue:
- https://projects.eclipse.org/projects/modeling.tmf.xtext
- https://projects.eclipse.org/projects/tools.acute
- https://projects.eclipse.org/projects/technology.rcptt
- https://projects.eclipse.org/projects/modeling.viatra
- https://projects.eclipse.org/projects/tools.buildship
- ...
## Steps to reproduce
- Go to an arbitrary project website that publishes their artifacts to the Eclipse marketplace.
- Click on the Marketplace link
## What is the current bug behavior?
The link leads to a 404.

## What is the expected correct behavior?
The corresponding marketplace entry should be shown.

## Priority
- [ ] Urgent
- [ ] High
- [x] Medium
- [ ] Low
## Severity
- [ ] Blocker
- [ ] Major
- [x] Normal
- [ ] Low
## Impact
Users have to search for the projects manually on the marketplace.
issue