Add 'Pause' Functionality for Journeys

Description:
Introduce a "Pause" functionality for journeys, allowing temporary halts without permanently stopping them. This would help address short-term issues while preserving the integrity of the journey data.

Why is this feature important to you:
A "Pause" feature provides flexibility in managing journeys by enabling quick fixes without disrupting the entire process. It ensures that IDs remain consistent and avoids mixing or fragmenting reports, which is essential for accurate performance analysis.

How would you like the feature to work:
The system should include a "Pause" button alongside the existing "Run," "Stop," and "Close" options. When paused, the journey should retain its current state and resume seamlessly once issues are resolved, with all IDs and reporting data remaining intact.

Current Behaviour:
Currently, the only available options are to run, close, or stop a journey. Stopping a journey disrupts continuity, alters IDs, and complicates reporting, making it difficult to manage temporary interruptions effectively.