feat(llc, samples): improve follow counts

[renefloor]

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Closes FLU-302

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• The code changes follow best practices
• Code changes are tested (add some information if not applicable)

Description of the pull request

In the example app we were following other users. We should post to the user feed and follow other timeline feeds.
The profile also reflects this by showing the followers of the timeline feed and the following of the user feed.

I added some logic to the sdk to update the follow counts on the feed on follow events.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 20.90%. Comparing base (3a66b67) to head (c0a79b6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #49      +/-   ##
==========================================
+ Coverage   12.80%   20.90%   +8.09%     
==========================================
  Files         120      120              
  Lines        3271     3287      +16     
==========================================
+ Hits          419      687     +268     
+ Misses       2852     2600     -252     

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