cache: Introduce partial SourceVersion support

This is the first step that introduces a 1:1 mapping between version
and source version. In a future version this can use the fields
currently marked unavailable to deduplicate the SourceVersion
objects across the group.

The policy gains a member for storing pins for sourceversions.

Together, in the future we should be able to determine candidates
for source versions.

0 files changed, 0 insertions, 0 deletions