[mathiasrw]

Closes #808

Stacked on #807.

Change

When the code of --js fails, only the message is told, as a panic:

> echo -n foo | rexreplace o 'nope()' --js
 ❌ The code of --js failed for the piped data: ReferenceError: nope is not defined
    No further processing.

Before, the stack trace of the runtime showed all the code put in front of the code of the user (the numbers of #791 with their cousins), about a screen long.

• It is a panic (exit code 3), as code that fails for one file most often fails for all. The files after it are not changed.
• The message says which file, or the piped data.
• It is the same for a syntax error and for an error when the code runs, once per file or once per match, in the sync and the async flow.
• The error is in errors in the status report.

Also in this PR

The help for --simulate says: "Execute everything during a run except changes RexReplace would normally make to the file system. Code from --js still runs, and can change data even with --simulate." (This PR gave it another text. #838 changed it to this one.)

Tests

yarn test-ci passes: the demo on Node and Bun, and 1024 Bun tests. test/fix/808.test.js is new. Five tests expected the error of the code to come out of the engine, and now check the message and the exit code 3.