tests: preserve logs on LibGoalFixture failure

[algorandskiy]

Summary

With extra logging the most recent failure showed node cannot stop properly but by the time of detecting this all data dirs (and logs) are gone since the test itself competed OK.
This PR propagates facts about how a node was terminated (term vs kill) so LibGoalFuxture can know it and preserve node.log for future analysis.
Also added debugging logs into node.Stop since it appears to be blocked by some service, and corrected missing new lines in LibGoalFixture stderr logging.

Test Plan

Tested manually: made algod not reacting to SIGTERM, node controller used SIGKILL. This was logged and data dirs with logs remained preserved.

[codecov]

Codecov Report

Attention: Patch coverage is 63.15789% with 14 lines in your changes missing coverage. Please review.

Project coverage is 55.89%. Comparing base (4e116cb) to head (ff456cf).
Report is 1 commits behind head on master.

Files	Patch %	Lines
netdeploy/network.go	0.00%	9 Missing ⚠️
nodecontrol/algodControl.go	0.00%	3 Missing ⚠️
catchup/catchpointService.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6030      +/-   ##
==========================================
+ Coverage   55.86%   55.89%   +0.03%     
==========================================
  Files         482      482              
  Lines       68475    68508      +33     
==========================================
+ Hits        38253    38294      +41     
+ Misses      27620    27616       -4     
+ Partials     2602     2598       -4     

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