feat: support to preheat multiple files

[gaius-qi]

Description

This pull request introduces enhancements to the preheat job creation logic, making it more flexible and robust by supporting multiple file URLs and improving parameter validation. It also includes minor updates to comments for better clarity.

Enhancements to preheat job creation:

• Added validation to ensure the URL parameter is required for image preheat jobs. If URL is missing, an error is returned. (manager/job/preheat.go, manager/job/preheat.goR119-R140)
• Enhanced file preheat jobs to support both a single URL and multiple URLs. If both are provided, URLs takes precedence, and the URL is appended to the list of URLs. Validation ensures at least one of URL or URLs is provided. (manager/job/preheat.go, [1] [2]

Updates to type definitions:

• Clarified the comment for the Type field in CreatePreheatJobRequest to reflect its purpose more accurately. (manager/types/job.go, manager/types/job.goL94-R94)
• Updated the URL field comment in PreheatArgs to indicate it can represent either an image or file URL. Added a new URLs field to support multiple file URLs, with a note on its priority relative to URL. (manager/types/job.go, manager/types/job.goL111-R117)

Related Issue

Motivation and Context

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[Liam-Zhao]

LGTM

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 15 lines in your changes missing coverage. Please review.

Project coverage is 34.30%. Comparing base (50083ff) to head (9c6f48d).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
manager/job/preheat.go	0.00%	15 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3997      +/-   ##
==========================================
- Coverage   34.31%   34.30%   -0.02%     
==========================================
  Files         342      342              
  Lines       40139    40150      +11     
==========================================
- Hits        13775    13774       -1     
- Misses      25454    25466      +12     
  Partials      910      910              

Flag	Coverage Δ
unittests	34.30% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
manager/job/preheat.go	44.01% <0.00%> (-1.78%)	⬇️

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[chlins]

lgtm

[Liam-Zhao]

LGTM