Fix #2475: Add support for sealed records and records with interface

[yyjdelete]

Link to issue(s) this covers

Problem

#2475

Solution

• Any comments on the approach taken, its consistency with surrounding code, etc.
• Which part of this PR is most in need of attention/improvement?
• At least one test covering the code changed

[siegfriedpammer]

Thanks for contributing this feature... the changes are looking good. Will take a more in-depth look once I get around implementing record struct.