feat: add prefetch to trigger seed peer downloads entire task

[gaius-qi]

Description

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.

[codecov]

Codecov Report

Merging #2929 (6a6dbc9) into main (1d75ddf) will increase coverage by 0.10%.
The diff coverage is 71.77%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2929      +/-   ##
==========================================
+ Coverage   51.02%   51.12%   +0.10%     
==========================================
  Files         161      161              
  Lines       21786    21838      +52     
==========================================
+ Hits        11116    11165      +49     
- Misses      10010    10012       +2     
- Partials      660      661       +1     

Flag	Coverage Δ
Object-compatibility-e2etests	?
e2etests	?
unittests	51.12% <71.77%> (+0.10%)	⬆️

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

Files	Coverage Δ
scheduler/service/service_v1.go	80.08% <91.78%> (+0.39%)	⬆️
scheduler/service/service_v2.go	84.89% <43.13%> (+0.04%)	⬆️

... and 2 files with indirect coverage changes