fix: wait for HTTP server serve() termination

[rogercoll]

Fixes #347

[codecov]

Codecov Report

Attention: Patch coverage is 65.00000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 78.46%. Comparing base (d1dbd0c) to head (cb710d3).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
server/serverimpl.go	65.00%	6 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #348      +/-   ##
==========================================
+ Coverage   78.35%   78.46%   +0.11%     
==========================================
  Files          25       25              
  Lines        2402     2419      +17     
==========================================
+ Hits         1882     1898      +16     
- Misses        412      413       +1     
  Partials      108      108              

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[tigrannajaryan]

Please update doc-comment of OpAMPServer.Stop() to explain that it waits until the server socket is released.

[rogercoll]

looks like there is an unrelated flaky test on the examples:
2025/02/13 14:49:28.332879 [OPAMP] Could not load TLS config, working without TLS: open ../../certs/certs/ca.cert.pem: no such file or directory

[rogercoll]

related data race issue #256

[tigrannajaryan]

related data race issue #256

I rerun the build a couple times and it fails. Perhaps this PR changed timings and the race is now encountered more consistently. Regardless of the reason I can't merge the PR if the build does not pass. We need to fix #256 first.

[rogercoll]

@tigrannajaryan The race condition test is now green after merging main. There are some changes on the files related to formatting which I think it would be better to tackle in a separate PR: #356

[tigrannajaryan]

@tigrannajaryan The race condition test is now green after merging main. There are some changes on the files related to formatting which I think it would be better to tackle in a separate PR: #356

Excellent! Let's get #356 merged and then we will merge this one. Thank you for your patience and for going the extra mile.

[rogercoll]

@tigrannajaryan The race condition test is now green after merging main. There are some changes on the files related to formatting which I think it would be better to tackle in a separate PR: #356

Excellent! Let's get #356 merged and then we will merge this one. Thank you for your patience and for going the extra mile.

Thanks for your review! Rebased 👍