fix sending cancels when excluding peer

[gammazero]

When sending cancels for want-block and want-have requests, a peer may be excluded because it was the sender of a block and that peer will cancel the want itself without having to receive a cancel message. The would-be sender of the cancel message still needs to do everything, such as adjusting want counts, as if the cancel were being sent and then not send out the cancel message.

Closes #694

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.47%. Comparing base (9d04741) to head (2d4df29).
Report is 2 commits behind head on main.

@@            Coverage Diff             @@
##             main     #805      +/-   ##
==========================================
- Coverage   60.47%   60.47%   -0.01%     
==========================================
  Files         244      244              
  Lines       31102    31106       +4     
==========================================
+ Hits        18809    18811       +2     
- Misses      10616    10618       +2     
  Partials     1677     1677              

Files with missing lines	Coverage Δ
...wap/client/internal/peermanager/peerwantmanager.go	88.69% <100.00%> (+0.15%)	⬆️

... and 9 files with indirect coverage changes

[lidel]

Not familiar with wantlist internals, but staging test suggests metric is fixed:

staging 01 – 0.32.1
staging 02 - kubo master / this PR

Before this PR

We had metric go negative on box 02:

With this PR

Metric seems to be fixed: