Support for Sidekiq 8

[jukra]

This pull request introduces support for the refactored web UI in Sidekiq 8, while trying to maintain backward compatibility with earlier versions.

Key Changes

1. Added conditional logic for web helpers to support both the old and new implementation. Changed the names of few methods to avoid conflicts (safe_*)
2. New initialisation code for the web extension for Sidekiq 8
3. Test setup for Sidekiq 8

This still needs more testing, and ofc the official release of Sidekiq 8

[jukra]

Removed the previous formatting change from lock_args_spec.rb which failed the specs in GitHub actions