feat: implement DeleteSeedPeer api in manager

[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 #2591 (ae16b58) into main (b723181) will decrease coverage by 0.08%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #2591      +/-   ##
==========================================
- Coverage   51.68%   51.61%   -0.08%     
==========================================
  Files         158      158              
  Lines       21006    21017      +11     
==========================================
- Hits        10857    10847      -10     
- Misses       9531     9549      +18     
- Partials      618      621       +3     

Flag	Coverage Δ
Object-compatibility-e2etests	?
e2etests	?
unittests	51.61% <0.00%> (-0.08%)	⬇️

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

Files Changed	Coverage Δ
manager/rpcserver/manager_server_v2.go	0.00% <0.00%> (ø)

... and 4 files with indirect coverage changes

[hyy0322]

lgtm