bugfix: log errors from event handlers

[Sikora00]

Add log when event handler faced an error
before the app crash

Refs #409

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

When an event handler faces an uncaught error the app is crashing without any information of the source of the problem.

Issue Number: #409

What is the new behavior?

We get information that the crash is caused by a specific event handler.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information