test: improve assertion messages

Print content of domain stack if it doesn't match expected values
PR-URL: https://github.com/nodejs/node/pull/16885


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>