Merge the relationship resolution rework

Done as a merge to aid bisecting IFF it ever becomes necessary

Wide testing indicates zero need for downstream changes (aside from several
warnings)

diff --cc Changes
index 91c525b,91c525b..abf2636
--- 1/Changes
--- 2/Changes
+++ b/Changes
@@@ -40,6 -40,6 +40,9 @@@ Revision history for DBIx::Clas
            of Schema/Result/ResultSet classes loudly alerting the end user to
            potential extremely hard-to-diagnose pitfalls ( RT#93976, also fully
            addresses https://blog.afoolishmanifesto.com/posts/mros-and-you/ )
++        - A new low-level API for relationship resolution is available as an
++          official method ( $rsrc->resolve_relationship_condition ). This is
++          mainly of interest to builders of reflection tools
          - InflateColumn::DateTime now accepts the ecosystem-standard option
            'time_zone', in addition to the DBIC-only 'timezone' (GH#28)
          - Massively optimised literal SQL snippet scanner - fixes all known
@@@ -68,6 -68,6 +71,8 @@@
            create()/populate()
          - Fix spurious warning on MSSQL cursor invalidation retries (RT#102166)
          - Fix incorrect ::Storage->_ping() behavior under Sybase (RT#114214)
++        - Fix some corner cases of non-fatal failures during relationship
++          resolution showing up as hard errors
          - Fix several corner cases with Many2Many over custom relationships
          - Fix intermittent failure to infer the CASCADE attributes of relations
            during deployment_statements()/deploy()