feat: added jobservice schedule subcommand

[NishchayRajput]

Description

Briefly describe what this pull request does and why the change is needed.

This PR adds schedule management commands under harbor jobservice schedules to improve Job Service Dashboard parity for CLI users.
It enables listing schedules, checking global scheduler status, and pausing or resuming all schedules from the CLI.

• Fixes [feature]: Implementing Jobservice Dashboard in CLI #774

Type of Change

Please select the relevant type.

• Bug fix
• New feature
• Documentation update
• Refactor
• Chore / maintenance

Changes

• Added schedule command group support: list, status, pause-all, resume-all.
• Added schedule API handlers and schedule table/status rendering support.
• Added schedule command docs (CLI docs + man pages) and schedule helper unit tests.

Command and Flag Behavior

Commands added

• harbor jobservice schedules list
• harbor jobservice schedules status
• harbor jobservice schedules pause-all
• harbor jobservice schedules resume-all

Supported flags by command

• harbor jobservice schedules list

  • --page
  • --page-size
  • supports global --output-format json|yaml

• harbor jobservice schedules status

  • no schedule-specific flags
  • supports global --output-format json|yaml

• harbor jobservice schedules pause-all

  • no schedule-specific flags

• harbor jobservice schedules resume-all

  • no schedule-specific flags

Default behavior

• list uses page 1 and page-size 20 when flags are omitted.
• status reports the global scheduler state for job_type=all.
• pause-all and resume-all operate directly on the global scheduler and are non-interactive.

[NucleoFusion]

Can you convert this to a draft, since this would cause conflicts with the other PR #793
And we can wait till the other gets merged