Add ability to clone pipeline schedules

What does this MR do and why?

This change introduces a clone feature for CI/CD pipeline schedules, allowing users to duplicate existing schedules with all their configurations including cron expressions, timezone settings, variables, and inputs.

Changes include:

• Added clone button to pipeline schedules table
• Implemented cloning logic in Vue component
• Added GraphQL resolver support for fetching schedule by ID
• Fixed Global ID parsing in pipeline schedules resolver
• Added permission checks for clone functionality

Changelog: added

References

Closes #30122

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Create a scheduled pipeline.
2. Go to the scheduled pipelines page.
3. Click the new "Clone pipeline" button.
4. Note that the pipeline is pre-populated with the cloned pipeline's configuration.