Log name of class that failed to obtain exclusive lease

What does this MR do?

This enhancement adds name of class that failed to obtain exclusive lease to help with diagnostics.

Screenshots

Originally only error (without class's name where error occurred) is logged to application.log:

Cannot obtain an exclusive lease. There must be another instance already in execution.

With this patch also the name of class that failed to obtain exclusive lease is logged to help diagnose that problem, for example:

Cannot obtain an exclusive lease for Ci::PipelineProcessing::AtomicProcessingService. There must be another instance already in execution.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team