p2p: reduce severity of failed capabilities advertisement

[algorandskiy]

Summary

We observe quite a lot of messages failed to advertise for capability gossip: context deadline exceeded in telemetry.
From DHT source code it is not quite clear where the context.DeadlineExceeded returned from - from finding peers or from sending to some particular peer.

It looks more probable tho it could fetch some peers and attempts to send out capabilities. Following this assumption, this PR increases probability of advertising more by shuffling capabilities array before re-attempt. It also looks like the 10s repeat timeout is too short, so increased to 100s.

Test Plan

Existing tests

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.

Project coverage is 51.81%. Comparing base (f13575c) to head (67f5be4).
Report is 5 commits behind head on master.

Files with missing lines	Patch %	Lines
network/p2p/capabilities.go	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6318      +/-   ##
==========================================
- Coverage   51.84%   51.81%   -0.03%     
==========================================
  Files         652      652              
  Lines       87442    87446       +4     
==========================================
- Hits        45331    45314      -17     
- Misses      39244    39263      +19     
- Partials     2867     2869       +2     

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