resolveOrCreateCommonThirdParty lived as a package-level helper in the
tracker mapping worker, but the common pattern enrichment worker now
reuses it. Homing shared catalog logic in a mapping-named file made the
enrichment worker quietly depend on the mapping worker's file, and it is
not a mapping concern.
Move it to pkg/thirdparty as exported ResolveOrCreateCommonThirdParty,
decoupled from cookiebanner's TrackerMappingAgentResult (it now takes a
name and category) to avoid an import cycle. It stays a transaction-
scoped free function so both workers compose it into their own tx for
atomicity rather than receiving a service that owns its own connection.
Relocate the catalog dedup DB test alongside it.
Signed-off-by: Émile Ré <emile@probo.com>
8d5571cf91