expose crypto/tls errors on the TransportError

[marten-seemann]

Fixes #3730. This was a lot less painful than I expected.

@aschmahmann Could you try this out and see if it resolves the problem you encountered in libp2p/go-libp2p#2451. A quick review of this PR would be appreciated :)

[codecov]

Codecov Report

Merging #4015 (f45847b) into master (f7f4872) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4015      +/-   ##
==========================================
+ Coverage   83.23%   83.24%   +0.01%     
==========================================
  Files         147      147              
  Lines       14800    14806       +6     
==========================================
+ Hits        12318    12324       +6     
  Misses       1983     1983              
  Partials      499      499              

Files Changed	Coverage Δ
internal/handshake/crypto_setup.go	57.17% <100.00%> (+0.09%)	⬆️
internal/qerr/errors.go	94.55% <100.00%> (+0.55%)	⬆️

[aschmahmann]

@marten-seemann thanks for the quick 😜 PR and review. From what I can tell this looks reasonable, although I'm not familiar with this code base.

However, I'm having trouble testing it because this change comes after dropping quic draft 29 and go-libp2p doesn't have a PR that deletes that dependency yet so I get compile errors. (Note: I accidentally pointed you at the what seems to be the right place to make a change since the code got shuffled a bit in between the version of quic-go I was using and master).

WDYT, should we wait until after there's a go-libp2p PR that drops draft-29 support and revisit this afterwards?

[marten-seemann]

Yes, that makes sense. We're planning to update to quic-go v0.37 in our next release, so it should only be a week or two until we can test this. I'll ping you again then :)