Option to exclude/include dependencies on other projects

Currently dependencies on issues in other projects are shown. This should be optional. It would be good to have the option of transitively following those dependencies to their end nodes too, although that's more complex and requires extra queries.

No files, tests, or entry points are named. Start by tracing where dependencies on issues in other projects are queried and displayed; done means cross-project dependencies can be excluded or included, with transitive following treated as the more complex optional behavior.

Written by the indexing model from the issue text.