`QueryFactory` support for 5-level parent-child relationship subqueries

[b-bowers]

Any plans to support 5-level nested sub-queries released with Apex version 61.0?

Saw this comment in the QueryFactory code.

[daveespo]

I'm closing this as a duplicate of #494 -- I just proposed a PR against that issue to remove the limit -- hopefully we'll get that merged up quickly