Test companionCapGrantRules, sourcesHaveWildcard, sourcesHaveDangerAll,
srcIPsWithRoutes, the FilterAllowAll fix for grant-only policies,
compileViaGrant, compileGrantWithAutogroupSelf grant paths, and
destinationsToNetPortRange autogroup:internet skipping.
51 subtests across 8 test functions covering all grant-specific code
paths in filter.go that previously had no test coverage.
Updates #2180