1.48.5 - Miscellaneous bug fixes

What's Changed

Miscellaneous bug fixes by @gwynne in #610

This update contains the following fixes and changes:

• Logging (especially of Fluent queries) is now done in structured fashion using metadata, as recommended for logging in libraries.
• Several superfluous Sendable workarounds have been removed (they were never needed).
• Resolved several DocC warnings.
• When using eager loading with @CompositeChildren properties, specifying withDeleted: true now works (previously the flag was ignored).
• query.aggregate(.custom(.sql(...))) now works correctly (previously only plain strings were handled for custom aggregates)
• Fixed a FluentBenchmarks test so that it actually tests what it claims to.
• Fixed numerous FluentBenchmarks tests so they no longer crash if something goes wrong during migrations.
• ISO8601TimestampFormat now correctly respects the milliseconds setting on a case-by-case basis when used in both modes in the same application (the behavior was previously nondeterministic).

This patch was released by @gwynne

Full Changelog: 1.48.4...1.48.5