Fix remaining skipped tests

[ryanio]

This PR:

• Resolves the remaining skipped tests in the test suite
• Updates testdouble from require to import
• Improves some testdouble usage for easier readability

Some good knowledge in the testdouble docs, including Using with TypeScript.

[codecov]

Codecov Report

Merging #182 (bbfe03f) into master (dc3bbbf) will increase coverage by 15.77%.
The diff coverage is 86.36%.

@@             Coverage Diff             @@
##           master     #182       +/-   ##
===========================================
+ Coverage   71.52%   87.30%   +15.77%     
===========================================
  Files          39       39               
  Lines        1447     1441        -6     
  Branches      231      229        -2     
===========================================
+ Hits         1035     1258      +223     
+ Misses        329      100      -229     
  Partials       83       83               

Impacted Files	Coverage Δ
lib/config.ts	65.30% <ø> (-2.05%)	⬇️
lib/net/peer/libp2pnode.ts	93.33% <ø> (+33.33%)	⬆️
lib/sync/fetcher/fetcher.ts	78.84% <ø> (ø)
lib/sync/sync.ts	81.81% <ø> (+6.06%)	⬆️
lib/net/peerpool.ts	73.13% <50.00%> (+1.49%)	⬆️
lib/blockchain/chain.ts	97.29% <100.00%> (ø)
lib/logging.ts	73.33% <100.00%> (-13.34%)	⬇️
lib/net/peer/rlpxpeer.ts	85.45% <100.00%> (+74.54%)	⬆️
lib/net/protocol/lesprotocol.ts	86.00% <100.00%> (+14.00%)	⬆️
lib/net/server/libp2pserver.ts	92.04% <100.00%> (+78.21%)	⬆️
... and 20 more

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[holgerd77]

This PR is incredible and really a milestone for the library - really amazing, thanks Ryan, wasn't fully aware yet on the amount of changes here when I mentioned this yesterday in the chat. Really great that you could preserve the testdouble functionality respectively adopt the code, especially since me and Chris were already somewhat convinced that there would likely be no other way than to rip out and replace the library.

Sorry for the lack of review comments here, I was on mobile while reviewing most of the time and too lazy for commenting, but I also would have had just some mild comments or inquires. I nevertheless gave this a full hour of review, so I would regard this safe to merge, also considering the nature of the changes.

Many of the local changes still feel a bit like magic to me 😝 , still impressed and also a bit puzzled that you found solutions for all this, I would have never managed to get there TBH. Maybe you can give us some introduction to the testdouble library when there is occasion, I still have got my problems to read (or: understand) the testdouble code parts to full extend. Can also recommend to others to keep this PR in mind as a potential educational source. I would assume this can be helpful to look at the updates here on occasions when one wants to understand parts of the test code functionality.

Anyhow. Great work! 😄 👍

Will approve and merge.