Add download URLs for binaries and sources to ApplicationComponent

[ohecker]

As a user of Solicitor I like to include links/URLs in my reports which can be used for downloading the binaries and sources of components.

Currently there is some related functionality / data in ApplicationComponent :

• Property ossHomepage - which might point to web homepage of the component
• Property sourceRepoUrl - which might point to some version control system which hosts the components source code
• Furtheron there is some functionality related to PackageUrls to derive the default source archive URL from the PackageUrl. This is used within the current scancode integration to create scripts for downloading the sources.

Especially when using the scancode integration there might be the case that the sources of a component are not available at the standard location (like e.g. Maven Central). If sources are then probably downloaded manually from some other location it is currently not possible to include this non default URLs in reports.

Proposal is to add two new properties to ApplicationComponent:

• packageDownloadUrl: URL for downloading the component (binaries)
• sourceDownloadUrl: URL for downloading the sources of the component

When not using the Scancode integration these URLs should be set to defaults based on the PackageUrl (possibility to override this via rules is currently out of scope).

When using the Scancode integration these two URLs should be read from a file origin.yaml which is stored in the same directory as the components scancode data. For any successful download of sources via the scancode integration scripts this file should be created automatically. In case that automatic downloads fails this file could be created manually.