Add support for R CRAN repository

### Current Behavior

R is widely used in data analysis and web application development across different industries. It would be great to add built-in repository support for CRAN.

### Proposed Behavior

Adding support for CRAN repository:
https://cran.r-project.org/

### 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