Add option to build embedd broker as shared library

[NorbertHeusser]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.62%. Comparing base (3c1a8c1) to head (9886279).
Report is 23 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3057      +/-   ##
===========================================
+ Coverage    81.35%   81.62%   +0.26%     
===========================================
  Files          191      196       +5     
  Lines        31780    32163     +383     
===========================================
+ Hits         25855    26253     +398     
+ Misses        5925     5910      -15     

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[RimonGazi]

Could you kindly provide an update on when this feature is expected to be merged and available?

[NorbertHeusser]

Right now some builds are failing and I have to rebase the branch to the latest development branch before it maybe merged.
Will take a look, if I can find some time in the next days to update this PR.

As the PR is targeting the develop branch it will get into official broker packages anyway some time in the future. As I needed the change in one of my private projects I back ported the changes to the current 2.0.20 version. If you need a version like this you may pick the source from my fork: https://github.com/NorbertHeusser/mosquitto/releases/tag/v2.0.20-embedd-broker.

If there is an interest into this change in general I may try to make a different PR targeting the current master branch. But it's not my decision, if this change is considered a "fix" and maybe merged into the master branch.

[NorbertHeusser]

Updated the PR to the latest develop branch. Looks like the build issues are in the develop branch and not related to this change.

[RimonGazi]

Thanks for the update, @NorbertHeusser! I really appreciate the effort you've put into rebasing this to the latest develop branch. It's good to know that the build issues are related to the develop branch and not your changes.

Also, thank you for providing the link to the v2.0.20-embedded-broker release — that will definitely be helpful for anyone needing it before the feature is merged.

Looking forward to seeing this feature merged once the issues are resolved. Thanks again for your hard work and for keeping us updated!