Draft: Truncate command output when debugging

What does this MR do?

Truncate the std output and std error of commands executed by Shell#execute to 1000 chars when they're flushed to the log, in the record method. This happens when the debug mode is enabled, or when the command being executed fails.

See https://gitlab.com/gitlab-org/security-products/analyzers/license-finder/-/jobs/1884226143#L473

What are the relevant issue numbers?

gitlab-org/gitlab#339031 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Job definition example
  • CI Templates (to be removed)
  • Vendored CI Templates (also in CE)
  • Ensure that all of the ENV vars supported are propagated to Docker containers upon docker run in job definitions
• Conforms to the code review guidelines
• Security reports checked/validated by reviewer