assert: refine assertion message

This makes sure that the error message is more appropriate than
before by checking closer what operator is used and which is not.

It also increases the total number of lines printed to the user.

PR-URL: https://github.com/nodejs/node/pull/27525


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>