Add a Skyframe injected value representing a Blacklist of package patterns. Any Package name starting with a blacklisted prefix is treated as a deleted package.

Note the relation to prior art in Blaze:
1. Deleted packages indicates to Blaze to pretend certain packages do not exist. The deleted packages are passed in as fully resolved package names. This is important because the invalidation logic when these values changes references the exact package names, as opposed to prefix patterns.
2. Negative patterns in target parsing. (eg, "foo/..., -foo/bar/..."). Note that if //foo:biz depends on //foo/bar:bang, we still visit that dependency. In other words, the negative patterns just control the target pattern parsing, but not the later evaluation of those targets.

Blacklisting acts like both (1) and (2), but in the form of a Precomputed injected value (so modifying the value would be more expensive than modifying deleted_packages).

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MOS_MIGRATED_REVID=107431993