assert: use error diffs in throws messages

This switches the assert.throws output to the one used in strict mode if a error object is used for comparison. From now on it will show the complete difference between two objects instead of only showing the first failing property.

It also fixes detecting properties with a undefined value and fails in case the thrown error does not contain the value at all.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines