Fix counts for joined query builders

[code-troll]

Summary

• Fix pagination counts with joined query builders by relying on TypeORM's getCount() so totals are de-duplicated like getMany.
• Add a regression test that covers a join producing duplicate rows to ensure totals match the distinct root entities.

Problem

• The library cloned the query builder and ran SELECT COUNT(*) FROM (<join query>) for totals.
• When joins multiply rows per entity (e.g., many-to-many or one-to-many), the page results were distinct but the total used the raw row count, inflating totalItems/totalPages and creating empty pages.

Change

• Clear pagination/order clauses on the cloned builder and call getCount(); TypeORM injects the same DISTINCT-on-PK logic used for paged selects.
• Added paginate.query.builder.distinct-count.spec.ts to prove joined queries now report correct totals.

Side Effects / Compatibility

• Totals on joined queries will drop to the correct distinct-entity count; if any consumers relied on the old overcounted totals, they will see smaller numbers (desired fix).
• Behavior now follows TypeORM getCount() semantics (e.g., honors groupBy the same way TypeORM does) and still issues one count query plus one data query.