Detect bound hardware when processing record elements (backport #3037) (#3115)

* Detect bound hardware when processing record elements (#3037)

Use new private Record._elements to validate Record elements. This
allows us to check invariants earlier than on cloning or binding.

(cherry picked from commit a8515661

)

# Conflicts:
#	core/src/main/scala/chisel3/internal/BiConnect.scala
#	core/src/main/scala/chisel3/internal/MonoConnect.scala

* Fix backport conflicts

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Co-authored-by: Aditya Naik <91489422+adkian-sifive@users.noreply.github.com>
Co-authored-by: Jack Koenig <koenig@sifive.com>